


The Shadow of Bodies

by lawsontl



Category: Supernatural
Genre: Alternate Universe - Canon Divergence, Angst, Canon Divergence, Demon Dean, Demon Dean Winchester, Dubious Consent, Episode Tag, Gratuitous Abuse of Latin, Human Castiel, Human Castiel in the Bunker, M/M, Mark of Cain, Mark of Cain Cure, Newly Human Castiel, Post-Episode: s09e23, Post-Episode: s09e23 Do You Believe In Miracles?, Pre-Mark of Cain, Sam Ships It, So Kripke'd It's Like He Had a Love Child With Joss Whedon
Language: English
Status: Completed
Published: 2016-07-23
Updated: 2016-07-23
Packaged: 2018-07-26 08:23:01
Rating: Mature
Warnings: Graphic Depictions Of Violence
Chapters: 5
Words: 20,655
Publisher: archiveofourown.org
Story URL: https://archiveofourown.org/works/7567054
Author URL: https://archiveofourown.org/users/lawsontl/pseuds/lawsontl
Summary: <blockquote class="userstuff">
              <p>A very Kripke'd S9 Hellatus Fic. Demon!Dean meets Human!Cas. It's not pretty, but it is pretty painful. </p><p>Giant, fluffy piles of thanks are due to 51stCenturyFox and Treefrogie84, who provided beta from both ends of the spectrum. I needed cheerleading as much as I needed an in-depth edit. As always, the good bits are their fault, the mistakes are mine.</p>
            </blockquote>





	1. Chapter 1

**Author's Note:**

> _"We should not be greatly surprised, therefore, if in accordance with the disposition of Him who grants us what is essential… sometimes no shadows whatsoever follow for those who receive; sometimes there are shadows for a few things, but not for all; and sometimes they are smaller by comparison with those granted to others. As he, then, who seeks the rays of the sun neither rejoices nor grieves whether the shadow of bodies be present or absent, seeing that he has what is most necessary as long as he receives the light… we shall not waste words over such an insignificant thing as a shadow."_
> 
> From: Exhortation to Martyrdom, Issue 19, the works of Origen.

It's been two days since Metatron killed Dean. Two days of slogging through enough celestial bureaucracy that Castiel could move on without Heaven going to Hell in a handbasket. Not that he would ever admit it to Crowley, but he's pretty sure Hell's orderly structure would be an improvement.

By the time he pulls into the bunker's garage, his eyes are stinging, head aching from the endless scrape of windshield wipers as he fought his way through the supercell hanging over the Great Plains. The smell infesting the Continental isn't some random road funk, either: it's him. He stinks of sweat and stress and too much time spent in the same clothes.

His right hand shakes noticeably as he pulls the keys from the ignition. A nap would help. He'd snuck in a few between strategy sessions, and that's kept his mind fresh even if it hasn't done much for his overall energy levels. Dean is the only thing that's kept him going through the eleven hour drive, and he's not going to nap now, of all times. The fact he's able to park indoors instead of getting drenched is because Dean gave him a key to the garage.

Dean looked out for him.

Metatron's bloodstained angel blade flashes through his memory, and he chokes down the feelings once again, transmutes them into the final push he'll need to pay his respects. He owes Dean that much.

It never occurred to him that instead of finding Sam grieving over Dean's corpse, he would find him in the library, books around him in sloppy piles. There's an empty liquor bottle tipped on the floor, and Sam looks worse than Castiel does, which is saying something. Sam's hair is limp and stringy. His rumpled grey tee shirt has a stain that might be coffee, might be blood. It's hard to say from a distance, especially when compared to the dark circles under his eyes.

"Hello, Sam."

Sam startles, hefting an enormous book from the table as he leaps out of his chair. It's millimeters from Castiel's skull before he realizes who he's about to whack. "Jesus, Cas!" He drops the book, chest still heaving. "What took you so long? I've been praying for days."

Castiel lifts the car keys by way of answer, staring at the floor. He's reasonably sure what he's feeling is some flavor of humiliation.

"Huh. I'd've thought you'd be flying the friendly skies again."

"Metatron was imprisoned. Heaven was restored. My grace? Not so much."

"Damn." Sam doesn't say anything else, just rubs his neck with one ink-stained hand. They had suspected that the spell to close Heaven would have destroyed Castiel's grace. There's a curious kind of comfort in sharing the confirmation.

"So," Cas ventures, glancing towards the dormitory. "Dean? I'd like to see him before―"

"You can't."

The two steps to the nearest chair suddenly feel too far, so Castiel sags to the floor instead. There's nothing left to hold him together now. He rests his face in sweaty palms, a deep pain taking root in his chest. "I should've called, but my phone was broken, and I couldn't find a payphone, so I drove, I just... I drove as fast as I could, and I didn't think you would... not so soon, because the Mark, his soul, Lucifer, you would wait, at least until..." He's aware he's babbling, that babbling is not something he's ever done before, but he doesn't care. _Too late. Too late. Too late._

"He left."

Confused, Cas drags his head up. "Is this a traditional platitude offered as a means of consoling the bereaved? Because I don't find it helpful."

"No." Sam is smiling, but it's not joy. It's the sort of smile that, were it on anyone but Sam, would signal that the time had come to back away slowly. "No, I mean, he left-left. Wrote me a note and everything."

"But Metatron killed him."

"I know. I was there. Guess you didn't get my voice-mail or my prayers, huh?"

Sam is no doubt thinking the lack of communication is because of the stolen grace, but Castiel can't bring himself to admit it's got nothing to do with it. He turned off angel radio because he couldn’t bear hearing Sam's grief any more than he could bear hearing the brothers and sisters who reveled at Dean’s passing.

Sam steps over and squats in front of him, hands on his knees so they're eye to eye. "Cas." He clears his throat, shifts his center of gravity, then starts over. "Cas, Dean is, well, he didn't…" Sam drags a hand across his face, exhaling sharply. "He's alive. Technically."

"I don't understand."

"He's possessed."

"Shit."

**

Rested, showered, and wearing fresh clothing, Castiel returns to the library. Sam's hair is clean now, and he's changed clothes, too, but it's debatable whether sleep had also been on his agenda. The mound of books has expanded, looking more and more like a leather-bound cephalopod, tentacles stretching across the table. Sam, sitting in what would be the beast's abdomen, offers Cas a half smile, gesturing to the chair opposite him. A microwave burrito and a glass of whiskey await.

"Clothes fit okay? I figured you were closer to Dean's size than mine."

"Yes. Thank you," Castiel says. "Other than feeling a bit warm from my shower, I feel almost human again."

Sam looks up. "That a good thing?"

"Jury's still out." He sniffs at the burrito. It's nearly room temperature, so it doesn’t smell like much of anything, not even its component molecules. Based on that, he takes a small bite. It's bland, unlike the burritos they bought from the elderly Sonoran lady in Smith Center. Very disappointing. But his vessel needs fuel, so he continues to eat. He takes another bite before asking, "I assume we are looking for information on possession and on the Mark."

"You assume right." Sam shoves a book towards him, tapping the cover. A cloud of dust rises beneath his fingertip, but Sam waves it away, unperturbed.

"I doubt there's more than we've already discussed."

"At this point, I'm willing to consider anything, even if it comes from Penthouse Forum."

Castiel tilts his head to one side, feigning deep thought. "Dear Penthouse, my brother took the Mark of Cain, and I wouldn't believe what happened next if it hadn't happened to me."

Sam snorts out a laugh. "I'm not sure what's more disturbing: you making that joke or that it means God reads bad porn."

"Not anymore, he doesn't." Cas opens his book, feeling the tiniest bit of satisfaction in knowing Metatron doesn't have as much as a pamphlet in his cell. So what if the book smells a bit like it was stored near spoiled potatoes? It's a book, and it’s more than Metatron will ever have again.

Four hours pass without a single useful revelation. They know that Cain and Abel had major sibling issues, no matter how the murder is portrayed. They know that the Men of Letters weren't above gossiping about their fellows in the margin notes of texts. And they have discovered that Cas is a fan of Kentucky bourbon. It's eased the burden of research, perhaps to the point of distraction.

"Black eyes, the whole shebang?" Cas asks, incredulous.

"Clear as day on the Gas-n-Sip security video." Sam is sprawled loose-limbed in his chair. "And the anti-possession tattoo was still intact when I brought him here. I checked. Refill?"

"Please." Sam adds more bourbon to both their glasses. Cas collects his own to inspect it. It's fascinating how the crystal cut-work refracts prisms of light throughout the honey colored drink. "Why'd they call this a finger, you think? Why not use more precise measurements like ounces? Or, or… millimeters?"

"Because everyone had fingers, but not everyone owned a scale."

"Shut up, Dean, I'm making a point here."

Cas takes another swallow. He's just anticipating the pleasant burn in his throat when realization sends the bourbon spraying out his nostrils across several priceless texts.

"Hey, guys." Dean gives a little wave from the head of the table, not looking threatening, exactly, but definitely a bit cagey. He blinks, and his eyes turn black. "Right, that's probably weird. Um…" He squints in concentration, feet shifting. When he blinks again, everything's back to normal, relatively speaking. However, even with his stolen grace nearly burned out, Cas can see the oily darkness shifting and slithering inside Dean's body. It's no hitchhiker; it's Dean's soul. "Still learning to control the eyes. And the zapping. That's handy, but it's got an itchy trigger finger."

"Emily Post probably didn't think to write a chapter on that, huh?" Sam asks, brandishing a tarnished katana. While Cas was trying not to choke, Sam had armed himself from one of the displays.

Belatedly, Castiel hauls himself upright. Sweat coats his skin, but he chalks it up to the alcohol and unsheathes his angel blade, ready to cover Sam's six. Well, technically his nine, but he's pretty sure it's the intent that matters, not the actual location on the clock face.

Dean raises both hands. "Easy there, fellas, I'm just here to get some of my stuff."

"It's not your stuff!" Sam slaps the broad side of the sword on Dean's chest. "That stuff belongs to my brother."

"Sam, it's him," Cas says, but Dean's reply drowns him out.

"Gimme a silver knife. Holy water. Borax. I'll do the drill." He's yanking aside his shirt collar to show his anti-possession tattoo even as he makes the offer. It's all so very Dean that Cas finds himself fighting the urge to go to him. Instead, he holds still, heart pounding in his chest from the relief of seeing Dean alive in any form.

"Sam," Cas repeats, louder this time. "It's really Dean."

Sam stares at him incredulously. "Not a meat suit?"

"No. It is Dean's soul, although it has been profaned."

"Yeah, well, you're no great shakes yourself, there, pal." Dean looks him up and down, then snorts. "Chrysler Building? More like a Quonset hut."

Sam lowers the sword a few degrees. "How'd you get back in here? I didn't summon you, and we're warded to the gills against demons. Even with the key, you shouldn't have been able to cross the threshold."

Cas has actually been pondering this very question since wiping the bourbon from his chin, and he's got a theory. "The Dresden Files."

"I'm not a dem... what'd you just say?"

"The Dresden Files. Oh. Oh, this is fascinating. The warding the Men of Letters used isn't as rudimentary as a salt line. It's far more subtle. I mean…" He waves a hand around trying to put words to the thought. It's thirsty work. "One moment." After a quick scan of the table, he finds his glass and finishes the drink Dean interrupted. "Okay. Crowley couldn't just walk in, but he could be invited in, or hauled in, as the case may be." He taps his chin with one finger, thinking aloud. "He wasn't miserable when he was in here, at least no more miserable than you wanted him to be―"

"Are you wasted?"

Cas frowns at Dean. "What does my state of inebriation have to do with the validity of my theory?"

"He's wasted." This time, it's not a question, and it's aimed at Sam.

"A bit." Dean rolls his eyes, but Sam's lips flatten into a grim line of disapproval. "Don't. Guy's got a right. In the last couple of days, he's lost an army, escaped prison, overthrown God Jr., learned you were dead, and, oh yeah, found out you're a demon not long before you dropped by to pick up your toothbrush and tighty-whities."

"I am not a demon!" Dean stomps a foot, a vein bulging on his forehead. Cas watches his mutant soul thrash against its cage, determined to break loose, but Dean storms away to walk it off at the opposite end of the room. When he returns, his eyes are black, but everything else about him projects stillness and calm. He stares at Sam defiantly.

A mistake, of course.

"So, if you're not a demon, then what the Hell are you?" Sam asks too loudly. "Because I hauled your corpse back here, and I'm still trying to get the blood out of my shirt."

"Look, I'll buy you a new shirt, Jesus Chr..."

Just like that, Dean is gone. Sam and Cas stare at each other, incredulous, but before either of them can utter a word, Dean reappears with an audible snap.

"I've really gotta learn to watch my choice of words. I blast off faster than a horny nerd dry humping the prom queen."

Sam doesn't blink, which is impressive. Cas leans back, curious how this is going to play out. "So you were telling Sam how you're not a demon?"

"No! I mean, yes, I'm not a―"

"―Hey, Dean?" Sam waves his hand like an eager student.

"What?"

"Christo."

"Sonofa―"

Dean disappears again. Sam snorts. Cas takes a deep breath, eyes darting between the empty space Dean once occupied and Sam, who has collapsed back into his chair, eyes wide with impending delirium. It's a very reasonable response.

"How long do you think he'll stay gone?"

Sam shakes his head. "Dunno, but when he does come back, we should have a trap set."

"―bitch!" Dean smacks the table, and energy ripples across. Two stacks of books fall over, and Sam grabs the sword just in time to keep it from getting buried under ancient literature. Dean's hands fly back up, though he continues to huff angrily. "Sammy, stop dicking around. I just want a couple things, okay?"

"Exorcizamus te, omnis immundus spiritus―"

"Really?"

Dean's shoulders sag before he disappears again. It's tempting to believe he's chosen to leave, but this is Dean. Sam and Castiel lock eyes. "Bedroom," they agree in unison before rushing to the dormitory. As expected, Dean's in his room, already filling a duffel bag. As soon as he spots them, he lifts a hand, bowing his head in concentration. Before they can decide whether to duck or cover, the door slams shut.

A triumphant "Hah!" echoes from behind it. Sam doesn't bother trying the knob, but Cas does. For form's sake.

"It's locked," he mutters.

"Now what?"

"Well, it is Dean's room."

"No, I mean," Sam waves for Cas to follow, and they lean against the opposite wall. In a low voice, he continues. "I don't think a salt line outside his door's going to cut it if the bunker's warding isn't doing jack."

"He's got the super suit but not the manual. We don't know what we don't know."

"If the dungeon could hold Crowley, it should be able to hold whatever Dean is."

"I suspect Dean may be Anakin to Crowley's Palpatine."

Sam stares at him curiously. Dean’s making a bizarre growling noise in the bedroom that Castiel hopes is a bad imitation of a Wookie instead of another sign of the Mark's influence. Without wasting time on discussion, they put more distance between themselves and the bedroom.

"Whatever we do, Cas, we need to get on it, because he won't just sit around and wait for us to decide."

"I don't believe we have sufficient knowledge to contain him here. The Mark makes him unpredictable."

"Yeah. Okay." Sam swipes his hand through his hair, pulling it back hard enough that his face distorts. "Okay." A clump of hair falls over his eyes when he lets go, and he blows it away. "We summon him once we have an actual plan. Until then, we let him leave."

"I don't think you're gonna be _letting_ me do anything." Out of nowhere, Dean's standing next to them. Cas jumps back a step, and Dean chuckles. "Gotta admit, that feels good after so many years of you making me shit myself."

Sam folds his arms while Cas takes another step away. They’re not laughing. Dean sighs, but his body language is all wrong: back stiff, arms ramrod straight and ending on clenched fists. Worse, there's a faint glow near his right elbow. Sam sees it the same time Cas does, and they share a worried glance. In a fit of senseless Winchester optimism, Sam decides to move closer to his brother.

"At the warehouse, just before you died, you said you were afraid of what the Mark was making you. Remember?"

"Yeah, well, shit happens."

"Stay. Let us help you."

"And make it worse? I'm cutting my losses." He whips his hand through the air at waist height, but Sam snatches it before he can finish.

"By becoming one of Crowley's minions?"

Dean jerks loose. "I don't like it, either, but he knows more about what's happening to me than anyone else. When I've learned what I need, I'll ditch the training wheels."

"Like we were going to kill him after ganking Abaddon?" Sam shouts. "There's always some excuse to keep that bastard around!"

Cas tries to follow the motion of Sam’s arms as they swing wide, but he fails. His vision skews one direction while his body, his sense of self, skews another. He has to press his temples between thumb and forefingers just to be able to talk. "Cain will know more than Crowley."

"Don't even think about it!" Dean snaps. "Even if you could find him, which you won't, it's not safe." Cas's head is pounding in time with his heartbeat, but it's not enough to keep him from noticing the grim expression on Dean's face as he addresses his brother. "Take care of Cas. He's the only family you got left."

"Don't give me that bullshit!"

Dean growls again, and this time, it's definitely not a Wookie imitation. His soul thrashes, unleashing a blast of raw energy that makes them wobble on their feet. Cas braces himself against the wall, self-preservation overriding all other urges, but Sam holds his ground.

"So the game gets a little rough, and you throw in the towel?"

"I ain't gonna take the bait." Dean spins around and has gone several steps before he comes stalking back, finger pointed in accusation. "You ever wonder why Hell's varsity hasn't done us in before now? 'Cause we're useful." He beats his palm on his chest, his voice shaking in time with the slaps. "Useful fucking idiots. Well, I'm sick of being useful to them. Now I'm gonna be useful to me, and no Dr. Phil psychobabble you fling at me'll change that." Any vestige of control is gone, eyes flaring black, teeth bared like a dog ready to attack. "I gave my life to hunting. What'd it get me? Kebabed by an angel blade. Not zesty!"

"But you're not dead!" Sam pleads. "That means we can find a way to turn this around."

"Who says I want to?" A disquieting breeze rustles through the hall, and the Mark glows brighter on Dean's forearm. "I'm making goddamn lemonade, and if you dipshits try to summon me, I ain't playing nice. Capisce?" Castiel nods, taking Sam's elbow, but he's got no strength to back it up. Sam slips from his grip at the exact moment Dean disappears.

"Damnit!" Sam kicks the wall.

Cas would like to say something optimistic, or at least supportive, but words aren't coming. He’s too distracted by how the hallway is moving. It's shaking erratically, a bit like a satellite wobbling in orbit, and it's all he can manage just to stay upright. He's not sure how much longer he'll be able to do that, so he drops to the floor. It doesn't help. If anything, it feels like he let go of the ground, and now he's moving, too. "Something's wrong."

"That's an understatement." Sam's words are clipped with bitterness.

"With me. I've got the spins."

It's unnerving how quickly Sam laughs at that, but Cas forces a tentative smile in response, hoping he will explain when he stops. After catching his breath, Sam looks up. "Cas, dude, I know it's awesome flexing Metatron's upload, but you don't have to do it in every sentence."

"Fine. I am experiencing severe vertigo." His stomach lurches into his throat. "And I may regurgitate."

Sam flips from jovial to serious in an instant, kneeling in front of him. "You're burning up." He leaves his hand on Castiel's forehead, nudging him backwards to get his eyes into the light from the ceiling. "How long has this been going on?"

"Since before I arrived at the bunker, but it was never this bad." He lowers his head, blinking away the whirling afterimage of the light fixture while Sam offers a hand.

"Can you walk?"

"That depends."

"On?"

"On whether those black spots are the result of Fred Jones getting his psychokinetic…" He wants to say more, something along the lines of Dean leaving behind little puffs of smoke like a Looney Toons character, only he can't speak. The spots are crowding together, blocking his field of vision until there's nothing left but a dim circle that seems to be collapsing inwards.

_That's all folks._

 


	2. Chapter 2

"Here." Sitting on the edge of Dean's bed, Sam lifts up Cas's head and tilts a glass of water to his lips. "Sip."

Cas doesn't remember most of the hour that's apparently passed since Dean disappeared, only the overwhelming stench of ammonium carbonate, Sam shaking him, and cold. Far too much cold.

His hair's still wet from the icy shower he'd been shoved into after Sam declared he was running a dangerous fever, so water is pretty low on the list of things he's interested in. Still, he takes a dutiful sip in deference to hydrating his vessel, then pushes the mug away. Sam puts it on the nightstand, light from the yellowed lampshade throwing his face into warm relief. 

"Feeling any better?"

"I am more comfortable. Yes."

Sam nods. He picks at a loose thread that's worked its way out of the inseam of his jeans while he weighs his words. When he finally speaks, it's with the gentle tone he usually saves for interviewing survivors of something particularly gruesome. "How much time have you got?"

Cas stares at his lap. "A few days at most."

Another nod. "And then what?"

"If I haven't replenished my grace, I die."

"So replenish it."

Sam's so earnest, so genuinely convinced of the rightness of his strategy, that Cas can't make the harsh comment that comes to mind. Instead, he says, "I won't kill another angel for their grace. I only did it the first time because he was about to kill me."

"Metatron!" Sam leans in closer, brows high in barely contained excitement. "Take his as punishment. An eye for an eye. Hammurabi 101."

Cas shakes his head. "That's not the problem, Sam. If it's not _my_ grace, it will eventually burn out no matter how I obtain it."

"Buy yourself some time."

"It's postponing the inevitable."

"Then postpone it! Don't just... just..." He waves his right hand in a circle, failing to find words.

"Give up. Like Dean." Cas can't look Sam in the eye any longer, so he examines the old record player to his left. Randomly, he wonders if there's any Glenn Miller in the collection the Men of Letters left behind. Lately, he's grown fond of the sound of muted trumpets, despite the symbolism humans attach to them. Or perhaps it's because of the symbolism…

Sam starts pacing the room with heavy steps. He's got his hands on his hips, muttering so loudly that Cas almost asks him to keep it down. But he doesn't. Just gives Sam the time to work through it.

"What if you get rid of it? Become human again?"

"That won't work."

"Why not?" He drops back down on the bed, hauling his long legs up and folding them into the lotus position. He counts off his points a finger at a time. "Anna tore out her grace and lived. Metatron cut out yours, and you lived. The way I see it, grace is like an organ for you guys. Your body's rejecting a transplant. So remove it, then we can figure out how to repair the damage."

It's tempting to believe it, but Cas has enough grace left to know more than the symptoms suggest. His body isn't ill; it's _failing_. "It's gone too far. The damage is no doubt irreversible at this point."

"Why'd you hang onto it so long, then?"

He shrugs. "I had a debt to settle, and that required me to be an angel."

"And you couldn't let someone else do it?"

"Is a Winchester attempting to scold me for going too far in the name of duty?"

"Yeah, well, Winchesters can change, too, remember?" They trade weak smiles before Sam thumps his hand on Cas's shin. "You get some rest. I'm gonna hit the books. If the Men of Letters knew enough about how grace works to develop a tracking spell, maybe they came up with something for this, too."

"You need to focus on helping Dean."

Sam leans over, hand still on Cas's leg. "I am."

**

The room is dark when Cas wakes up. One of the last things he remembers is Sam putting a record on the turntable. No Glenn Miller, as it turns out, but Nat King Cole was a perfectly acceptable substitute. Perhaps better. The hiss and pop of the needle riding the groove was nearly as mesmerizing as the deep baritone vocals and steady scrape of brushes on cymbals. 

The record player stopped quite a while ago, that he's sure of. The room is silent and dark, other than a wedge of light that filters through the grate at the bottom of the door, casting a pale checkerboard pattern on the floor.

Castiel scoots up far enough to feel around for the lamp on the nightstand. He flicks it on, and the sudden brightness makes him wince. He covers his eyes until they have time to adjust then grabs the rest of his water. The urge to gulp away the foul taste in his mouth is strong, but not strong enough to override the queasiness in his stomach. He sips carefully, giving the room a good look for the first time since Sam led him to it.

Dean’s careful collection of weapons, keepsakes, and curiosities has been plundered. Hooks hang empty on the walls, scraped paint the only sign that they’d once been used. The Bronze Age cross Dean salvaged from the charred wreck of Bobby’s house is now barely visible under a stained burlap sack. Cobwebs lie thick over the scattered books and photos that remain.

"Dean," Cas whispers. It's neither summoning nor prayer, just a half-formed wish that something could have gone well for once. Just once. Sighing, he lifts the blanket from his legs, only realizing as cool air strikes them that his clothes are damp with sweat. He shuffles to the sink on the far wall and splashes water on his face. Glancing up, he's caught off guard by the man with the sickly yellow skin staring from the mirror. It takes longer than it should for him to realize it’s him.

**

He's not surprised to find Sam in the library. What is surprising is that he’s not alone. Hannah is leaning over his shoulder, pointing to a line of text in a book with an enthusiastic smile animating her features. What is she doing out of Heaven? More importantly, what is she doing _in the bunker_?

"Hannah?"

Both people at the table turn his way, bearing similar expressions of concern, but only Hannah speaks. "Commander, you should be resting."

Cas shakes his head, letting go of the door frame so he can enter the room. The long walk to the library has taken what little energy he had, and the dark spots are back, dancing just out of reach. His knees buckle, but Sam catches him before he hits the floor. He ducks his shoulder under Cas's arm to help him to a chair.

"How long was I asleep?" There's a clock somewhere, but Castiel’s thoughts are muddied and everything seems blurry in this big, bright room.

"About 17 hours."

It seems like more. And less. "I'm very warm."

Sam looks at Hannah, brow furrowed. “I’ll go to the infirmary.”

She nods her reply.

Cas hasn't managed to collect his thoughts well enough to say anything to Hannah before Sam lopes back. He shakes several red capsules out of a bottle and puts them in front of Cas, sliding over a glass filled with some type of soft drink.

"Take those. It should be enough to bring your fever down. I know angel metabolism is pretty high, but I'm factoring that in. At least, I hope I am, but it's not enough to OD on if you're more human than not."

Cas stares at the glass. Bubbles are skittering up the sides, chasing each other like children playing tag. It reminds him of the Heaven belonging to a woman who'd always wanted to have a brood of children. She'd died in a car accident during the sixth month of her second pregnancy. Both girls had died with her. She spends an endless sunny afternoon watching them clamber on a playground, surrounded by dandelions gone to seed and launching wispy pods far and wide like a snowstorm.

"Cas, you in there?"

"What?" He notices the capsules and the beverage. Remembers why he's at the table. "Oh, right." Dutifully, he washes the medication down. "I'm not certain what this will accomplish."

Hannah shrugs. "It will ease your suffering until we can do something permanent." Confused, Castiel shakes his head as she continues, "I laid hands upon you while you slept. The damage is extensive."

"And?"

Sam begins pushing pink tablets through a foil packet. "Steroids would be better, but Benadryl will have to do until we get some."

"Soon." Hannah presses two fingers to her temple, bows her head in deep concentration. Cas doesn't dare trying to tune into what she's hearing. He doesn't think he could bear it if it didn’t work. "Flagstaff cannot come until she finishes her shift. We don't want her to look suspicious when supplies are found to be missing."

Sam hands over the latest medication, directing its consumption with a stern look that Cas can't help but obey. As he's about to pop the pills in his mouth, Sam puts a hand over his, "Wait. You shouldn't have all that on an empty stomach. Give me a minute."

He leaves the room, and Cas watches him go, still feeling like he's at least two steps behind everyone else in the room. Then, out of nowhere, his vision clears up. A hand is touching his forehead, but it's not searching for a fever. It is Hannah's hand, and her eyes are gentle, damp, as she grants him relief.

"Hannah, you..." He nearly chokes on the shame, barely managing to mutter, "You don't have to do that."

"Yes, I do. I didn't trust you when you needed me the most."

"Your decision was guided by logic, not spite."

She returns to her chair on the other side of the table, and though she's shifting books like she has a purpose, her eyes do not stray from his. "That doesn't mean it was the correct decision."

He can't face her, staring at a sigil laid out in granite on the floor instead. "Thank you." 

She doesn't reply, just focuses on arranging the materials in front of her.

Eventually, Castiel thinks to ask, "How is the council coming together?"

Her expression lightens. "We have contacted what remains of the factions. Most have selected a representative. Those who haven't intend to within the next two days."

"I hope it works out."

"It will. It was a wise suggestion to distribute the burden and temptations of leadership." She leans forward, hands folded comfortably over the freshly stacked books. "I still wish you had agreed to stay in Heaven. I'll do my best to fill your seat on the council, but you should become part of your own vision instead of―"

"Instead of this." He gestures to the room to signify his current situation.

"May I speak frankly?"

Thankfully, Sam returns before Cas can answer, setting a plate in front of him. On it is a sandwich: two slices of bread, peanut butter and...

"Grape jelly," Sam says, lips quirking up on one side. "Not jam." This time, Cas can't hold back the feelings. His chin trembles. He tries to hide the inconveniently human moment by grabbing the sandwich, but he's shaking so much that he fumbles it. "You okay?"

"Fine. I'm fine." 

Sam lays a hand on Cas's shoulder, and for the first time since he realized the stolen grace was killing him, Castiel feels real terror. What will become of him in death now that he's neither human nor angel? The question threatens to seize his every rational thought, but a fragment of discipline remains somewhere in there, and he's able to pull himself back together. He tries again for the sandwich, this time succeeding. 

The first bite is a mix of salty peanuts, tangy grapes, and yeasty bread. "It tastes just like it should," he says to Sam.

Hannah seems a little puzzled at why this should be noteworthy, but she doesn't question its relevance. Instead, she straightens her jacket and draws conversation back to their task.

"So we've compared notes and come up with―"

Cas interrupts, talking around a mouth full of sandwich. "Notes?"

"Yes, Commander. We have a unit dedicated to researching your condition." Her shoulders are squared, and she beams with a genuine pride that makes him feel guilty for considering she’d have done anything less.

"Oh."

"Sustainment via another angel's grace is very rare. It took us some time to find actual records from the occasions." She offers several documents as examples, fanning them out across the table until the final is placed on top. It's a scroll, and the vellum crackles as it tries to curl back into the shape it has held for centuries.

"What happened?" He has jelly on his fingertips, so he doesn’t touch the scroll to make it easier to read.

"All the angels involved died. But their motivation was power, not loyalty," she adds quickly, like she's trying to forestall an objection. She needn't have worried; he has no intention of interrupting another bite of his PB&J. It's probably the last true pleasure he'll experience, so he's being as mindful of it as he can under the circumstances. "None of them tried to remove the stolen grace when it started making them ill. Based on the evidence we have, and the way our vessels function when we inhabit this plane, I believe Sam's transplant theory is viable."

"I can't just rip out this grace."

Sam takes that as his cue. "You're right. If you'd had this kind of reaction as a plain old human, you'd be dead already. This grace is a Catch-22, it's killing you, but it's also keeping you alive. The trauma from ripping it out would be fatal." Cas shakes his head, mostly in disbelief at the time they’ve wasted considering this, but Sam raises a hand, staying the unexpressed doubt. "So we use the needle, like we did with the remnants of Gadreel's grace in me. Take it a bit at a time."

Hannah taps the table with her index finger drawing Cas's attention back to her, "You'll need human medical support throughout the whole process, which Flagstaff will coordinate through the hospital outreach program. We'll also have an angel on duty at all times to heal you after each extraction. If we are careful, we can do this."

It seems simple. Logical even. Which is why it's far too good to be true. He's between bites, so he speaks up. "And the catch is?"

"There's a risk of memory loss," Sam replies. He's apologetic, speaking soft and slow.

Clearly, he's also confused. "Grace is power, not consciousness, Sam."

"True, Commander, but your vessel's hippocampus is processing information at an incredible rate."

Cas pauses, mouth stretched over the sandwich. He pulls back, looking to Sam. "The hippocampus helps store long term memory. You think it's the retcon?"

"Yeah." 

Hannah looks confused. "What's a retcon?"

"You wouldn't understand the reference." The words are out before Cas can stop himself, and he chuckles. Sam laughs outright. For her part, Hannah doesn't look wounded, she just smiles at both of them as if she finds the whole interaction pleasing. The moment doesn't last, but it was definitely needed, and Sam is the one who restores their focus by clearing his throat. 

"The grace is getting it from all sides. It might have been able to hold out a bit longer if it hadn't had to divert so much energy to helping your brain integrate that gigantic memory dump."

"Those times when you slept in Heaven," Hannah asks, "did you experience a dreamlike state?"

Castiel flinches, uncomfortable that he hadn't successfully kept that to himself. But he should have known better; there's no such thing as privacy in Heaven. Not really. He nods once, and Hannah's response is nothing more than a tender smile. She turns to Sam.

"I believe that confirms your theory, then. Theo's grace did not restore him to a purely angelic state. He remains somewhat human. The only way to know how much is—"

"I can do the math," Castiel interrupts. He sags forward, feeling the weight of his decision in a literal sense.

"Take some time to think it over, Sir."

He nods. His appetite has gone, so he licks the jelly off his fingertips. The act gives him a bone-deep sense of joy. Of security. It makes no sense to him that this is so, but he finds he doesn't care. The reasons don't matter, only the possibilities. "Sam, what do you think I should do?"

Sam leans in, lower lip jutting out in an expression of equivocation. "Not my place to decide, Cas. But, whatever you do? I don't think you can have a foot in both camps anymore. You either have to figure out how to get more grace and live like an angel until it burns you out for good, or..." He rubs a hand over his chin. "Or, you commit to being human and all the crap that comes with it."

Cas takes a deep breath, pondering Sam's words. "So, I take the chance I might live, or I guarantee I die?" He stares at the remains of his sandwich, weighing his options, but it doesn't take him long to decide. "Let's get started before I get any worse."

**

By the time Flagstaff has everything prepared, Castiel can no longer walk. The situation becomes apparent after he fails to leave Dean's room unaided. Sam easily lifts him into his arms.

"You don't do anything half-assed, do you?" he asks, turning sideways to keep Cas's feet from hitting the door frame.

"No. I always put my whole ass into it." He lets his head fall against Sam's shoulder, enjoying the sound of his voice so close up.

"Smart-ass."

"You know, this is probably when Dean would point out that we're fixated on ass."

Sam doesn't answer, though he does smirk. Then, just as quickly as it came, it's gone. He stops.

"About Dean. I have to ask, so if I'm crossing a line―"

"Yes." Cas doesn't even need to hear the question. He's been expecting it, though maybe under different circumstances. "Dean is part of why I held onto the grace for so long, but Metatron was wrong thinking it was the only reason."

"Right. Sorry."

"Don't be." He lifts his head. Not as far as he'd like, but he's too wrung out to feel anything so trivial as embarrassment at this point. "Sam, this is important. Make sure the story is told properly." At that, Sam bends down, sliding his arm from under Cas's knees so he can stand again. Cas pulls up his borrowed jeans before bracing himself against the wall. "I took Theo's grace before the Mark was even a concern. Things with Heaven didn't go down quite as I'd hoped, but that doesn't matter. It was the right choice to keep the grace as long as I did."

"Because your angel army would never have rallied behind a human."

"Correct. And though Metatron turned them against me, even had the power of the Angel Tablet at his command, he overlooked a fundamental truth."

"Which was?"

"Being an angel is less about grace than it is about being part of the Host, being part of something greater than yourself. He believes I made my choices for the benefit of one man, but he was confessing his own mistake."

Sam huffs out a breath. "Projection of Biblical proportions, huh?"

"Very much so." He closes his eyes, steeling himself for what he knows is coming once they get to the infirmary. He remembers paralyzing pain when Metatron sliced away his grace, but that was merciful compared to what Sam had gone through when they extracted Gadreel's bit-by-bit. Pain has never been quite as intimidating as it is without Heavenly power to provide a buffer.

Still, he'll endure it. The only other option is a death postponed through barbarism, which does tend to put things into perspective.

A warm hand on his shoulder draws him from his thoughts. Sam, of course, face drawn with concern. "You ready for this, Cas?"

Castiel tugs at the black t-shirt he's wearing, smoothing out the faded Steve Miller Band logo. "Yes. Just one more thing."

"Sure."

He summons up the last of his courage. "If something happens to me, tell Dean―"

"I'm not telling Dean anything." Sam shakes his head adamantly. "You'll tell him."

Point taken, Cas manages a shrug. He's not feeling strong enough for more. Is pretty sure that what little he does feel is delusion, but he has to give Sam something in return. Evidently, Sam finds a shrug sufficient. 

He's probably used to accepting much less.


	3. Chapter 3

The infirmary has been transformed. Aside from the presence of several angels with human medical monitoring equipment, the examination chair has been laid flat, arms extended from the sides with straps attached to them. An IV stand is to the right, multicolored bags of fluids hanging from the hooks. A rolling table is covered with sharp implements in regimented rows. The syringe has pride of place, gleaming as it rests on a sterile cloth. 

Castiel swallows.

"Ready to go, Commander?" Flagstaff asks, her crisp surgical scrubs crackling softly as she walks his way.

"As ready I can be without a few shots of whiskey." The statement falls flat, forced bravado failing at this point. Strangely, his body has started to shiver even though he's quite warm against Sam's chest. Sam squeezes a bit harder in silent reassurance.

"I see you're already adapting to life among hunters." She purses her lips but keeps further judgment to herself as she beckons Sam to lay him in the chair. Two of the assisting angels show up, immediately beginning to strap him down. He tenses, hands balling into fists and spine arching up from the table. The doctor presses him back down easily, calming despite her strength. "It's safer if we keep your vessel as still as possible," she adds, the words firm but gentle. He wants to understand, but his heart feels like it's going to beat out of his chest, and he's seen what becomes of a human body when _that_ happens. "Don't worry. We'll be putting you under. You won't know a thing until it's all finished."

"That's not better." Too many memories are associated with being in this position, waking up with decades, even centuries, rearranged or removed. He does his best not to struggle, gaze darting around the room for something to distract himself. Finally, he spots Sam. He's behind a tripod, fiddling with a small video camera. After pressing a few buttons, he realizes he's being watched and immediately returns to Castiel's side.

"We're going to record everything so you know we didn't hypnotize you to dance like a chicken or something."

"Chickens are noble birds." It's not the kind of quip he'd have preferred to make, but the only reference coming to mind is a movie about chickens made of clay attempting to escape a farm. It doesn't seem particularly relevant, though he does empathize more than he ever expected possible.

"Okay. Well then, you can dance like one later when you feel up to it."

Still working on the chicken motif, his brain loads an image of people flapping their elbows to a fast-paced song involving an accordion. The ridiculousness of the dance makes him laugh, taking the edge off his nerves. He lets out a breath. "I'll do that."

Sam affectionately claps him on the cheek before returning to the camera. Cas watches as Flagstaff inserts a needle into the vein inside his elbow. She's barely finished the injection when a haze settles over him, and he's only half aware that someone has taken his head to wrap it with something. It's soft. 

He inhales. 

**

The first thing Castiel sees when he opens his eyes is a cell phone propped on a nightstand. He doesn't remember checking into a motel―which makes sense because he can't afford a motel―and this definitely isn't where he usually sleeps, so where is he? As he's about to roll over for a look at the rest of the room, he registers the sticky note on the phone's screen.

_Hit redial to call me – Sam_

Cas tries to pick up the phone, but his hands feel detached. It reminds him of the first time he'd occupied a vessel, the skill required to override the will of his host and manipulate the limbs. It takes deep concentration, but after a few seconds, his arm responds, then his hand. He brings the phone close enough to press the call key, but he's not quite able to manage something as complex as speaking once Sam has picked up. Evidently, that doesn't matter.

"Hey, buddy! Be right there."

Sam bounds into the room moments later, sporting his usual flannel shirt and a pair of jeans with hems so worn that strings drag the floor. By this time, Castiel has figured out he's in the bunker and has even managed to prop himself up, but he's at a loss for how an IV got into his arm.

"Here, let me help." Sam puts a water bottle on the nightstand. "That's for you." He untangles the IV line from the bedclothes and fluffs the pillows before standing back, a broad smile on his face.

"Why am…" Castiel coughs, and something thick loosens in his throat. He coughs again, clearing it with a grimace. "Why am I in Dean's bed?"

"You needed something more comfortable than a hospital bed. What's the last thing you remember?"

That's not much of an answer, but Sam doesn't look very disturbed at giving it, so it can't be all bad. Taking a moment to think things through, Cas settles on a mental image of cedar trees, an old motel, and wings burnt into a warehouse wall. "I was in Utah. Investigating a lead on Metatron."

"Damn." Sam rubs the back of his neck. "Well, we knew that could happen." As he walks over to Dean's desk, he asks more questions. "Do you remember the Horn of Gabriel? Metatron capturing you?"

"He captured me?" Cas looks down. He examines his wrists, lifts an unfamiliar black t-shirt but finds no injuries. "No. Sam, what happened?"

"Long story. Happy ending. Well, at least by our standards. Hannah sends her regrets, by the way, but she said she's glad you're finally awake." He offers up a laptop, already open to a document. "Before you ask who Hannah is, you'll find out in the message you left yourself." Cas is confused, switching between Sam and the text on screen, but Sam carries on with typical efficiency. "When you're done with that…" He holds up a small black card then inserts it into a slot beneath the keyboard. An application launches, showing an image of an empty examination table. "There's a bunch of video from the last five days. Some of it's kinda unpleasant, but, for the most part, you can fast forward through it. Unless you really like the idea of watching yourself sleep. I won't judge if that's your thing."

Cas is still staring dumbly when an unfamiliar woman enters the room wearing a white lab coat, her dark hair pulled into a thick ponytail that sweeps around her shoulder. "How are you feeling, Commander?"

"Commander?"

Sam chuckles. "Yeah, that's what we thought the first time we heard it, too." He thumps a meaty hand on Cas's shoulder, nods at the doctor―who returns the nod with obvious familiarity―then leaves. The doctor doesn’t wait for Cas to answer her question, just takes his wrist and begins timing his pulse. He glances at the computer while she does.

_If Sam gave this to you, it means you have experienced another significant memory loss. At least this time you chose it, and you should remember your own name._

Cas eyes the doctor. "I suspect we've met."

"Yes," she says, nodding matter-of-factly. "Your leadership helped us to reclaim Heaven."

The weight of the news lands square in the chest, and he realizes who, or more precisely, what, he is speaking with. "Our brothers and sisters, have they gone home?"

"Many have, sir. And we're working on releasing the souls trapped in the Veil. It's slow going, but it's finally happening."

"Good." He sighs, relaxing into the pillows and allowing her to continue to take his vitals. It's all the excitement he thinks he can handle. The sense of fatigue is nearly total, and it's not a feeling he likes, but he already suspects this outcome was the lesser of two evils.

That's usually how it goes.

The doctor seems to prefer silence to idle chatter. She does tell him that he's undergone a lengthy healing process―five days based on Sam's comments―and that he'd been resuscitated twice during that time, the first only by the barest of margins. While it's useful information, it doesn't clarify how it all came to pass. Still, he knows it's more important to let her do her job than to question what's already been done, so he doesn't protest as she runs him through a series of tests. She checks everything from his reflexes to his cognitive skills. After he proves he can recite the genealogy of Genesis while patting his head (a task he's not quite certain validates anything but a perverse sense of humor), she seems sufficiently appeased to remove the IV line. He's still rubbing at the bandage she placed over the puncture wound when she begins lining up bottles of pills and vitamins. The details on dosage begin to blur as his attention drifts back to the missing time. He's relieved when she takes his laptop and opens a file containing all the directions she's just given verbally.

"Not my first day out of med school, Commander," she says. "Now, if there's not a paragraph on this thing about how fantastic I am, you'd best write it."

As soon as she leaves the room, IV stand in tow, he takes a long and blessed drink of the bottled water Sam brought, moves to the desk, and gets down to his reading.

It never occurs to him to question what's in the document; he knows his own words when he sees them. He'd been cornered into a terrible choice and had been doing his best to create something positive from it. It certainly seems like he'd succeeded, quite possibly a first. Which makes it all the worse when he gets to the part describing the choices Dean had made during the same time period.

_…this led them to Cain, who gave Dean his mark._

Cas shoves the machine away, breath caught in his chest. He takes a moment to calm himself. Being human is inconvenient that way. Emotions, for all their breadth and depth, have one very annoying thing in common: they run roughshod over his rational mind when he's least prepared for it. One would think he would have been aware of that when writing the message to himself, that he'd have done something to soften the blow. Then again, he'd been an angel again for several months. Maybe that was long enough to forget how close to the surface everything feels. 

He'll get used to it like he did before. It's not like he has an alternative.

Returning to the document, he learns how he discovered the Mark, the order in which the effects began to manifest, and the theories he and Sam were developing. It's a rather dry exposition of facts and references, so he begins cataloging it as he reads, trying to reach conclusions he'd been unable to make before the healing began. 

Then the other shoe drops.

_Dean is now some type of demon. The easy answer is that he's a Knight of Hell because of Cain's involvement. But the knights were not simply marked, they were trained. Dean's demonic transformation occurred with unprecedented speed and is complicated by the fact that he remains in his own body._

_No one knows the implications. Least of all Dean. His behavior has been atypical for a demon. The one time we saw him, he tried to warn us off seeking Cain's advice. He is putting our safety before his, which gives me hope he's not beyond redemption._

A deep yawn interrupts his reading. He rides it out, arching over the back of the chair to stretch his spine. The need for sleep has crept up on him despite the deeply unsettling news, and he doesn't fight it. Unlike his hazy recall regarding emotions, he remembers quite clearly that avoiding sleep leads to muddled thinking and, cruelly, difficulty sleeping the next time he tries. It's another annoying part of being human, and, since this is the last body he'll have, he has to take care of it. 

With the laptop closed and the bedside lamp switched off, he dutifully climbs under the sheets, tucking the pillow under his head. Dean's bed feels very, very good. His bedroll at the Gas-N-Sip was sufficient, as was the bunk at St. Anne's, but this is positively luxuriant. No wonder Dean is so fond of it.

_Dean._

Dean is a _demon_. 

Dean, whose blankets, pillow, and mattress Cas is using. Probably even his clothes, now that he thinks about it. He's pretty sure the name on the t-shirt he's wearing belongs to one of the bands in Dean's box of audio cassettes.

And that thought leads to another. 

_Windows open on a humid night. His arm outstretched, palm buoyed by air currents as trees flash by in a kudzu-draped blur. Sam and Dean bickering about who is the better of two actors. The Impala's engine roaring, tearing down the road like she's as invested as them. Warm leather and hot asphalt. The frantic buzz of cicadas. Sweat._

Will they ever hunt together again? Or will it end with one of them killing Dean and dooming his soul back to Hell?

Castiel has no idea. An ache twists his stomach, and his eyes are beginning to well up. He knows exactly what that means, and he loathes it. Has since the first time, standing on that busy city street, overwhelmed by sights and sounds. 

Rubbing his eyes with the heels of his hands, he tries to keep the disagreeable emotion from going any further, as if he could somehow distract his tear ducts. When that fails, he sits up, taking deep, controlled breaths. If he can meditate, or at least center himself, that should keep everything from going off the rails. But despite every effort, his human body refuses to respond to logic. Instead, memories drift in of rain soaking him to the skin, the hard floor of the storage room, hunger so deep that he felt hollow. A tear escapes, and he wipes it away, smearing it resentfully onto the blanket. 

He should be grateful, not sad. After all, he's warm, dry, and sheltered. So why is his brain dredging up the past? How does remembering past vulnerability improve his current situation? It makes no evolutionary sense.

Dragging the pillow to his chest, he lays back down, curling around it. Humans respond positively to anterior contact, and the fetal position triggers a sense of security. But knowing that does nothing to actually make it true. After all, he has no vestigial memories of the womb to draw upon. His one unqualified success was raising Dean Winchester from Hell, and now even that's gone to shit.

Desperate, he shoves his face into the pillow. That helps... at least until he starts suffocating. When he's forced to come up to breathe, the battle is lost. A flood of tears cuts loose the moment he feels air on his face.

He has failed to prevent himself crying like he fails at everything. Failed as a human. Failed in Heaven. Got captured. Dean died waiting for him to destroy the Angel Tablet.

The man he'd been created to save, his best friend, the most important human being in his life, and he _failed_.

What's the point of fighting, then? There's nothing left to fight for. He's a human, Dean's a demon, and there's not a damned thing he can do about either.

**

He's not sure how long he's been weeping when Sam knocks, carrying a mug and speaking words that barely register through the morass of emotion. It's everything Cas can do to get air in and out of his lungs between the spasms that are racking his chest. Sam quickly abandons any sort of two-way conversation, pulling him into a hug instead.

"Hey, hey, it'll be okay." He roughs a hand up and down Castiel's spine, making a peculiar sibilant noise in time with the strokes. After getting past how odd that is, Cas realizes that it's soothing. Nothing like the susurrations of the Host, of course. More like waves at high tide, or dried leaves rustling in a breeze. He focuses on the sound, tuning his consciousness to it, and it begins to lull him, down, down and back to himself, back to a state resembling self-control.

"Something is wrong," he chokes out, and just in case Sam needs the clarification, he adds, "with me." 

"What?" Sam pulls back a bit, hands bracing Cas's shoulders as his eyes rush through a cursory examination. "What is it?"

He points to his face, stunned that Sam has missed the most obvious thing in the room. "I can't stop." 

At that, Sam laughs. It's abrupt, and he stops immediately when he sees Cas scowling. "Sorry. Sorry." He lifts his hands in mock surrender. "I know it sucks, but that's pretty normal, actually."

"It sucks?" He knows he's shouting, and that it's an overreaction, but he's unable to master that any more than he could master the tears. "This?" He gestures to his chest just as another spasm strikes. "This is awful. My nose is running, and my cheeks are raw. My head hurts." The spasm returns, yanking painfully at the base of his rib cage. "And this…" He waits until there's another attack, and it comes with annoying regularity. "What is wrong with my chest muscles?"

"You've never had hiccups before?"

"Yes, but from drinking a carbonated beverage too quickly. I understand how that can irritate my diaphragm. Not this."

"Sudden, extreme emotion can do it, too. It's…" Sam cringes before continuing, "it's really common in kids when they cry."

Now that he mentions it, Cas does recall Nora's infant daughter doing something similar during her crying spells. That makes him feel better for about two seconds, until he hiccups again. "So, I'm being infantile?"

"No. You're just inexperienced." Sam reaches into his back pocket, pulling out a bandana and gesturing vaguely towards Cas's face. "Here."

"Thank you," he mutters, blotting at his cheeks. The worn fabric is soft and smells of Sam. It's a good smell: laundry soap and... Well, as an angel, he could have identified the precise scents. From the origins of the cotton in his shirt to what he'd eaten for breakfast. Now it's just soap and something that smells like Sam, like his friend, and that's going to have to be good enough. "Why do people claim crying makes you feel better? I don't feel better. I feel worse."

"Well, usually it takes the edge off. Helps you think."

Cas snorts his disbelief. "I seem to be the exception to every rule." Drying the tears has helped a bit, though he's reluctant to admit it now that he's made such an issue of how unpleasant it is. 

"Seemed like being human came pretty naturally to you last time."

"I was acting the way I thought I should act. I didn't want…" He trails off, his face sufficiently dry to return the bandana, but Sam refuses it. 

"Didn't want what?" he asks, an eyebrow raised. He's doing that reassuring hand-on-the-shoulder thing again, and Cas knows he's not going to get away with keeping his thoughts to himself. He looks away.

"I didn't want Dean to see how difficult it was for me."

"Oh," Sam replies, and it's half word, half deep sigh. "Because he threw you out of here."

Castiel nods, breath catching on another chest spasm. When it passes, he starts folding the damp bandana into progressively smaller squares to give himself something to do that doesn't require eye contact. The longer he's human, the more he understands Dean's concern about personal space. Interaction can be so exhausting sometimes.

"Why would you protect Dean after that?"

"I wasn't protecting him. I was angry. I wanted to prove that I didn't need his help."

"Then you've got humanity down better than you realize." Sam doesn't elaborate, possibly waiting for a reply, but there's nothing else to add, really. "Here…" He holds up a mug that Cas hadn't noticed before now. "Drink this before it gets cold. Chicken soup. I figured you needed to eat something by now, but it ought to make you feel better, too."

"I appreciate that you're making sure I am nourished and hydrated. I don't take that for granted." 

"I know."

Despite low expectations, Cas takes a taste. Sam appears to have been right on this one. In addition to an exceptionally flavorful broth, the wisps of steam soothe the soreness from his eyes. He clings to the warm ceramic, exhaling into the mug so the steam will bloom upward and bathe his face. Even the next hiccup feels a little less annoying like this.

"You wanna talk about what's eating at you?"

Cas shakes his head, holding the mug close to his chest. "There's nothing to talk about, is there? Everything is in the past. There's no reason to be upset about it now."

"Really? Because you left yourself a friggin' novel on my laptop. That's a lot to take in at once: you're no longer an angel, you're cut off from your family, you're―"

"Alive." He takes a turn at resting a hand on Sam's shoulder. Sam is almost as surprised as he is that he does it. It doesn't feel completely natural, but, like hugging, Cas suspects it will begin to feel that way soon enough. "And I still have family."

Sam grins. "That's true. You do. But, well, it's kinda fucked up." He pauses, blinking. "Actually, it's a lot fucked up." He blinks some more then grabs the pillow that's been wadded up beside them, hugging it to his chest. "Move over. I'm gonna cry now."

Castiel laughs, regretting it immediately. It's very inappropriate after all the effort Sam has put into helping him get through his own emotional outburst. But Sam simply breaks into a grin at Cas's stammered apology, which means it was a farce meant to cheer him. Well, it worked. 

A half smile still on his lips, Cas takes another drink of the soup, and a small miracle follows. Without consciously choosing to do so, he breathes out long and slow. More of the discomfort seems to leave with the breath, so he repeats the behavior: drink, exhale, drink, exhale. By the time the mug is empty, he is lighter, somehow. Less physically distressed.

Better yet, the hiccups have stopped.

Feeling much more like himself, whoever that's going to be, he puts the mug back on the nightstand. "Sam, how does anyone ever master being human?"

He shakes his head. "I don't know that anyone has, except maybe Gandhi or Mother Teresa, and it took them a lifetime."

"I was created before humanity existed. You'd think I'd be further along."

"You are as determined as Dean to be a grouch!" The pillow strikes Castiel's arms with a painless whump, the end of it curving right into his hands. He snatches it on the first try, hiding it behind his back. Sam chuckles, rocking onto his heels. "You've been an actual human a grand total of, what, a year? And that's counting the time before we stopped the Apocalypse. You're a friggin' prodigy, Cas. At that age, most humans are still surprised by their own feet."

"My feet are not surprising, though they do smell unpleasant."

"Dude, it's not just your feet."

Cas decides now would be a good time to employ the pillow in his own defense. He lands what he hopes is an appropriate blow, knowing he should put enough force behind the strike to show respect for his opponent. Despite the restraint, Sam tumbles to the floor, limbs wheeling like a cartoon character. It should seem immature, unbecoming, but there's something deeply appealing about it. 

Even now, after all Sam has endured, he can make room for play. For joy. 

Cas is sporting a broad grin as Sam props his elbows on the mattress, pausing long enough to blow a clump of hair out of his eyes. "If you promise not to attack me again, I'll help you to the shower."

"I know the way." He drags his right leg from where it's been pinned under him. It begins to tingle, and he cringes, but he bears it with something like gratitude; the cause and cure are unequivocal. He appreciates that clarity for the blessing it is. "Though I suspect you intend to help me even if I don't want you to." 

Sam sticks out his elbow. "You really are a natural at being human."

"How's that?"

"Thirty odd years, Dean still hasn't figured that out."


	4. Chapter 4

One thing about being homeless is that it taught Castiel to sleep lightly. It's the third night since he became permanently mortal. On the first day, he'd focused on rebuilding his stamina while researching the Mark with Sam. On the second, Hannah had arrived with a stack of notes. After a somewhat awkward reintroduction, she'd brought them up to speed on several spells her research team thought might be useful with Dean. It had taken them well into the third evening to mix the formulas and paint the sigils. By the time Cas had finally convinced Sam to get some sleep, he was so tired he barely remembered crawling into Dean's bed.

Now, he's having one of those strange dreams, the kind where he's still doing all the things he'd done during the day. It's another thing he doesn't yet understand about being human. He'd always believed his father had devised dreams so the brain could improve its ability to meet survival needs during wakeful periods. But his brain doesn't seem to be learning anything now, just repeating what he already knows. Frankly, it's boring. Not at all the surreal and fantastic world he'd been led to expect. He’s almost grateful when a rustling noise wakes him. 

"Heya, Cas."

Castiel props himself up on an elbow, blinking a few times to make sure he's not wrong about the "being awake" part. He still finds some dreams difficult to distinguish from reality, so it's entirely possible this is all in his head. But it's definitely a corporeal version of Dean sitting in an actual desk chair, and he looks _wrong_. Reading about it on a computer screen is much different than seeing it in person. Dean looks defeated: shoulders sagging, pallid skin drawn tight under an unkempt beard, eyes rimmed red enough that it's obvious even in the dimly-lit room. 

_Black eyes._

"Yeah," Dean says in response to the flinch Cas can't avoid. "It happens without me meaning to. Gave up trying to control it. I got bigger fish to fry."

"You've been fishing?"

Dean laughs, but that's wrong, too, like he's working from muscle memory. "Sam told me you lost more than your wings when they disconnected you from the matrix."

"You talked to Sam?" Castiel scrubs at his eyes, sleep grit catching on his knuckles.

"Called ahead. I wasn't into getting my head chopped off for checking up on you, though he did tear me a new one for waiting so long after your, uh, procedure thingy."

"A call would have been sufficient."

"Didn't feel right." He shrugs. 

"A demon with a conscience?"

Dean doesn't reply immediately, and Cas doesn't press. He's too busy yawning. It's a big one: long and hard enough that his jaw pops. A smaller yawn follows, and it's almost disappointing by comparison. He's decided that he's fond of yawning, how it invigorates his senses, and he definitely needs that right now. Though by the time he's finished, Dean's attention has shifted.

"So, you're gonna be good?" Dean asks, voice flat. He seems to be examining a blank spot on the wall.

"It appears so."

"Good." He's still looking anywhere but at Cas, seeming almost dazed in his muddy boots, a knee bobbing even though the rest of him is motionless. Cas follows the shape of his body, notices Dean's left hand clamped over his right forearm, exactly where the Mark is located. His knuckles are white.

"Dean, are you okay?"

Turning the discussion around snaps Dean out of his reverie. He still doesn't look at Cas, but he shoots up from the chair. "Yup. I'm fan-damn-tastic. I'll get outta your hair."

Cas sits up the rest of the way. "Don't go."

"I’m a demon, man. I don't belong here." Dean closes his eyes, huffing out a breath, once, twice. When he opens his eyes again, they're green. Streaked with red and what looks like several broken blood vessels, but green. Human. Cas is just about to say something to that effect when Dean groans. He grits his teeth, fingers clenching his arm like he's scrabbling for the edge of a cliff, then, with a cringe, his eyes snap to black.

If that was supposed to prove a point, Dean's seriously miscalculated. 

"You are Dean Winchester, first born son of a union between a hunter and a United States Marine." Castiel begins kicking away the sheets. "You're a legacy of the Men of Letters. The Michael Sword. The Righteous Man." Legs freed, he turns around. A bit too fast, but he ignores the head rush. "You can be anywhere you want to be."

"This ain't a friggin' VISA commercial!" Dean stumbles backwards, stopping against the desk. "Just..." His jaw twitches, and he sighs, or maybe groans. It seems to be a combination of both. He gestures absently at the room. "My stuff, it's yours now."

Cas's heart sinks into his stomach. "Dean, I know I've failed you, but, please, do not give up so quickly."

"This ain't about giving up. I'm being practical. I don't need it. You do."

Castiel tries to get up, but his legs have other ideas. A combination of lingering toxins and sleep stiffness makes him wobble. Not much, but he doesn't immediately get his balance, either. Dean seems to materialize at his side, slinging an arm around his waist. 

"See? Nothing to apologize for. The demon thing's got bennies."

"I'm fine." The protest falls on ears as stubbornly deaf as Sam's, so he lets Dean guide him back to the bed. At least, that's what he's expecting. Instead, Dean pulls him in close. "What are you―" Callused fingertips stroke Cas's jawline, a knuckle catching under his chin and nudging it up. Cas sees Dean's closed eyes for less than a second before eyes don't matter because Dean is kissing him. It's brief, but it shakes him to his core. 

Of all the scenarios Castiel considered might take place with Dean as a demon, this hadn't made the cut. It hadn't even been on the _list_. 

"Dean?" 

Dean shakes his head instead of replying. Cas's jaw still cradled in his palm, he brings their foreheads together and breathes deeply, letting only a moment pass before ducking in to kiss him again. This time, it's more than just lips on lips. He puts his whole body into it: hands, arms, chest. Returning the kiss is as instinctive as breathing and as desperately satisfying as that first bite of food after too long hungry.

Grace or no grace, he's always felt like a student of humanity. He makes observations, but even when he's been human, he's always felt one step removed. Different. Kissing Dean makes him feel present, a spark in his chest and a surge of something elemental threading his nerves. 

Then Dean's tongue slips into his mouth, and it's enough to make Cas genuinely weak in the knees. He moves in closer for support, bringing their hips together, and is thrilled by the heat of it. Heat and the hint of an erection pressing against the top of his thigh. He can't help himself, rolling his hips without consciously deciding to, just knowing that it feels good. Dean feels good.

This makes sense. Everything flows instinctively, without need to examine or second guess. Humanity at its purest. The core drive instilled in all his father's creations: to join with a partner, to create pleasure, sometimes even a new life. 

It's beautiful.

The muscles in Dean's biceps twitch as Cas lowers his hands from his shoulders to pull him closer. He needs more contact, the proximity he's been denied since rebuilding Dean from earth and marrow. Under Cas's left hand, there's more of that beautiful warmth. But instead of being good, it's off somehow. Warm to the touch, but his mind keeps insisting that it's actually cold. Without breaking the kiss, he glances down. 

The Mark of Cain throbs beneath his palm, which can only mean one thing: this isn't actually Dean. At least not a Dean acting with full autonomy. The man Castiel knows would not be... well, he wouldn't be doing this. This isn't Dean Winchester; this is a demonic corruption of his soul, and Castiel is still too early in his recovery to take on a demon alone.

A simple "Christo" would fix matters. It would also make Dean mad enough that he wouldn't come back, undermining their plans to help him. So the smart move is to get help. Unfortunately, just as Cas has slipped his cell phone in hand to auto-dial Sam, Dean growls.

"No interruptions!" 

He yanks Cas's arm backwards at the elbow. The phone clatters to the floor, battery shooting across the room when the case breaks open. Swallowing dread, Cas looks up. Dean's eyes are no longer just black; they're empty. An absence of life that is as pure and absolute as the pain stabbing through Cas's shoulder.

"Damn, Cas, we coulda had such a good time," Dean continues, smiling like he's conjured a pleasant memory... if flayed skin and pooling blood can be considered pleasant. "But now? Well, you really shoulda had me leave." 

Castiel tries to pivot loose, a shout forming in his throat, but his legs are torn out from under him. Adrenaline floods his bloodstream as Dean slaps a hand over his mouth, shoving him to the mattress. He's no match for Dean's newly-minted strength, and the instinctive fear response nearly paralyzes him. 

Nearly, but not completely. 

He's a soldier, and a mortal body's instincts cannot override that even if it takes longer than it used to for his training to kick in. Deliberately, he slows his breathing, forces himself to think tactically. 

Fact: Dean's got him pinned but there are at least three ways he could break free despite his weakened state. 

Fact: the lamp on the bedside table would make a good bludgeon, and it's almost close enough to touch. 

Fact: his mouth is covered but not his nose, so this probably isn't leading to a kill. At least not a quick one. Though, if that's true, then what is it actually leading to?

The answer comes quickly enough. Dean gradually slides down, down, until his head is below Castiel's waist. Then he… sniffs. It's precise. Thorough. Like a snake tasting the air.

A low rumble of approval accompanies his deliberate journey back to Cas's throat, breath hot against the tendon joining shoulder to neck. A graze of teeth follows, and the jolt of pleasure kicks rational thought out of the room.

Maybe… 

It could… 

He _wants_.

"Like that?" Dean asks. 

Cas turns his head, baring more skin. Yes, like that. Of course, like that. Dean bites down. Not enough to break skin, but sharp and bright. Fear feeds arousal as teeth find the curve of his ear. His earlobe. The bolt of his jaw.

It's too much. 

It's not enough.

The hairs on his arms rise, mirroring his hips as he strains for more. Another nip on his chin. One on his Adam's apple. Each drawing a gasp because language is failing. Lips drag slowly along his collarbone, and he arches into them, only to be greeted by a full-on bite. He flinches away with a shout of betrayal.

"Aw, man!" Dean rears back, crowing with laughter as Cas checks for blood. Thankfully, there is none. "I've been thinking. You know how it is when you're all mojo'd up." He waves a hand to indicate Cas's body. "Well, okay, you used to. Anyhow, take you for example." He fists the neck of Cas's t-shirt, yanking him up so they're face to face again. "You've wanted me since you left that heavenly hickey on my shoulder." Not giving him a chance to blink, let alone respond, Dean kisses him roughly before shoving him away.

Cas scuttles backwards, but it's too little too late. He only puts a few inches between them before Dean straddles his thighs, pinning him properly this time. That rules out the lamp, and the only other thing in reach is a pillow, which isn't going to be much help seeing as, strictly speaking, Dean doesn't need to breathe. 

"'Course, Big Daddy ixnayed fraternizing with the humans." Dean forges on like this is no different than analyzing a hunt over a couple of beers. "Not that that stopped Anna. Man…" He licks his lips, eyelids flickering with a different kind of memory as he adjusts himself. He takes far longer than necessary, rubbing the heel of his hand over his crotch. "I fraternized her good." 

That night in the barn. The unpleasant churn in Castiel's stomach as he watched Dean kiss Anna goodbye. He hadn't understood the feeling then. Chalked it up to Jimmy's consciousness leaking through. But now he knows what it was: jealousy. The first foray into the human emotions that would ultimately land him in Naomi's tender care. Disgusted with how his body aches at the sight of Dean's grotesque display, he turns away.

"That's enough."

Dean ignores him, nuzzling his ear to whisper, "Every time you ride in the back of the Impala, you sit where that skank sucked me off." 

If any further proof was needed that this is the Mark's influence, that was it. Changing his strategy accordingly, Cas drags his hand around Dean's waistband. With a faked smile, he cups Dean's crotch.

"Oh?" Dean's brows arch high with interest.

"Well, I've never performed fellatio, but I could do this." He strokes until he's found Dean's penis, tracing it through well-worn denim. 

Dean laughs, and it's the good kind this time: deep and genuine. Almost lazily, he drapes himself over Cas, coming in for another kiss. Which does exactly what Cas was hoping for. Hips now free of Dean's weight, he bends his knees, ensuring he can get away as soon as he can disable Dean. And he'll do that, just as soon as he gets over how good it feels underneath him.

He's been estranged from the Host for so long that he's accustomed to being lonely, but that doesn't mean he likes it. Despite overwhelming proof to the contrary, having Dean's chest against his feels safe. He doesn't know what it means about him that it's true, but he also doesn't care. It's still Dean's body, Dean's heart beating against his, Dean's palms on his hips, Dean's groin working his legs open to rest there. Hard now. 

Ready. 

He doesn't realize he's moaned until Dean mutters approval, "That's how ya do it."

When their eyes meet again, Dean's are clear. Still streaked by exhaustion and shot with blood, but lucid. Like maybe, just maybe, it's _him_ after all: untainted by Cain's curse.

He braces Dean's jaw in his palms, searching for anything as confirmation. He wishes he could see his soul instead of relying on transient physical clues, but all he has to go on is his eyes. They seem alive again as he licks into Dean's mouth, biting on his lips, first the top, then the bottom, giving them the attention he’s been wanting to give for years. Tasting him, hungry for more, hips rising and falling, slow and steady.

Dean holds him tighter. 

_Yes._

Chest to chest. Bodies moving together in Dean's bed. This is good. Cas turns his attention to the stubble-covered contours of Dean's throat, sucking on the tight cord of muscle shifting below the skin. And the scent. God, the way Dean smells is remarkable: cardamom, leather, the perpetual tang of the Impala's exhaust, and... _no, please, no…_ sulfur. Just a whiff, not the characteristic stench that trails demons, but undeniably sulfur. 

It makes him angry. Determined to focus on what is right, not what his body wants. 

He is not an animal, powerless to the rut. He is rational. A being of morals even if the type of being has recently changed. And, most importantly, Dean needs his help. Channeling that certainty into something that he hopes looks enough like continued enthusiasm to keep the demon convinced, he returns his hand to Dean's crotch. Maybe he no longer has the ability to knock a person out with a touch, but there's a less-refined method which is just as effective. Working quickly, he unzips Dean's fly, shoving fabric aside so he can cup his testicles through his underpants. 

"You learn that from the pizza man, too?"

"No. I learned it from April." As Dean's interest turns to confusion, Cas squeezes hard.

It's not particularly surprising to get flung against a brick wall after that maneuver. The floor rises to meet him, knocking him breathless. Still, he's not as bad off as Dean, who is bent double and cursing with enough fluency to damn the human ancestors Castiel doesn't have. Something trickles down his neck as he climbs to his feet. He touches the back of his head, and his fingers come away bloody. Not really a good thing, but there's no dizziness, either, so it can be ignored until he and Sam have contained the demon. He's almost to the door when a wave of pressure slams into him, sweeping him away. 

"Now that was ballsy!" Dean bellows. Having recovered much faster than expected, he extends a hand and twists it, pinning Cas to the wall like he's adding him to the weapons display. Rolling off the bed, he jumps to his feet impossibly fast. A blink, and he's in Cas's face.

"Stupid... desperate... pathetic Castiel. Gave everything to save Heaven, then you screwed it up even worse." Teeth bared, nostrils flaring, Dean jostles closer just in time for Cas to pistol-whip him with a revolver torn from the wall. The invisible pressure eases up, but Dean's not out. Not by a long shot. 

Cas squares his shoulders, ready to strike again. "Metatron caused the angels to fall. Not me."

Dean spits blood to the floor. "You don't get it, do you? How the spell came together? Heart of a nephilim, cupid's bow, and―"

"―the grace of an angel. I know!" He growls as he slams the pistol grip into the other side of Dean's skull. It won't do much besides add a matching bruise, but it makes him feel better. Why does everyone feel the need to keep reminding him what he already knows?

"Ah, ah, not quite." Dean stabs his index finger into Cas's sternum. "Not just a base model angel. It had to be an angel with an options package."

Cas frowns. "A what?" 

"Something not every angel has. It had to be one that's in love with a human." 

Sweat drips down Castiel's forehead, or maybe it's blood. He's not sure it matters because it still burns his eyes. He knows he should shout for help, but what comes out instead is, "I don't understand."

"Man, you're not even gonna get a lousy copy of the home game!" Dean cocks his head sharply to one side. "That douchebag really had your number, didn't he? An angel so dumb he gave up a goddamn army for Dean fuckin' Winchester. Or so he could fuck Dean Winchester, but you just took a pass on that." He crowds in, pinning Cas with his chest. "Game over, man. You've fulfilled your destiny, angel of the Lord. How's it feel?"

Cas tries to reply. His lips move, tongue pressing against teeth to make sounds, but nothing comes out. Not even the hiss of air. 

"Neat trick, huh?" Dean giggles incoherently. "Been dying to try that." He punches Castiel's shoulder. "Get it? Dying!" He cackles, wiping fake tears from his eyes. Then, quick as switching channels, he rams his palm against Cas's throat, bloody spittle spraying out as he snarls, "Whatcha gonna do to save yourself now, mud monkey? Offer me your shiny new soul?"

Cas shakes his head, beginning to feel dizzy. He tries to swallow, but he can't. Dean's grip is too strong. Even putting everything he's got into it, the best he can do is rip Dean's sleeve at the shoulder. His lungs work fruitlessly, razors slicing his throat as his trachea begins to collapse. Hoping he hasn't waited too long, he sends up a prayer.

_Hannah, help me, please. Call Sam._

Oblivious, Dean kicks Cas's legs apart and grinds against him. "God, I was so damned repressed." He bucks his hips hard, grin knifelike. "Not anymore." 

The room is starting to dim. Cas claws at Dean's face. Nothing changes. Not even when he draws blood. Then, in a fit of desperation that he's sure would rival any Winchester, he finishes ripping off the sleeve and lays his hand on Dean's bicep. His own mark is long gone, but maybe that doesn't matter.

For one endless second, nothing happens. Hope drains away with consciousness. Then Dean jerks his head to the left, sizing up where he's being touched. He's completely expressionless, studying the hand on his skin like he's never seen fingers before. He blinks. Stares. Blinks again. The room starts fading around the edges. Another blink, then Dean staggers back. 

Castiel drops to his knees, choking as oxygen rushes into his lungs. One hand clings to his throat, protecting it as he rolls the desk chair in front of himself for cover. He's only just managed to take a normal breath when Dean is back, grabbing his ankle. Cas kicks out, expecting to be dragged away. But Dean isn't pulling him into danger, he's pulling him to the door.

"Cas, get out of here!" 

"Dean!" He lunges for his friend instead of trying to escape. "Stay with me."

"Get back!"

"No! Dean, keep fighting it. This isn't you!"

Without warning, the door slams open. Sam barrels into the room, a gout of holy water preceding him. It only takes him a fraction of a second to reconnoiter and correct his aim to soak Dean. Water sizzles when it touches skin, dropping Dean to his knees. They’ve almost taken control of the situation until the water makes contact with the Mark of Cain. It bursts into flame, and Dean stares at it in horror.

Then he screams.

More precisely, sound erupts from Dean's throat. Whether it's a scream or even human is hard to say, but it rolls through the room like an angry drunk. The desk lamp bobs several times before slamming into the opposite wall. It drops to the floor, neck bent double. Records rip from their sleeves and whip towards Sam. He ducks, but a disc still slices across his forearm. 

"Exorcizamus te!" Cas's shouted Latin gets a second volley of records in response. He dives to the floor.

"Omnis immundus spiritus!" Sam takes up the exorcism and is targeted not by records but by the entire record player. The aim is off, and it crashes into the wall, which is only a little better than a direct hit. Shrapnel bombards anything that's not covered, and Sam takes the worst of it. He drops down next to Cas, blood beginning to trickle over his brow.

"Omnis satanica potestas―"

"―omnis incursio infernalis―shit!"

The fire has spread up the remains of Dean's sleeve, heading towards his shoulder. His screaming continues unabated. 

"―adversarii, omnis legio."

Cas hauls himself up by the edge of the sink. He's deciding whether to use plain water or try smothering the fire with a towel when a book slams into his forehead. He shakes it off just in time for another book to follow, delivering a hardbound sucker punch.

"Cas!"

"I'm okay!" He crouches down, cradling the lump on his forehead as he continues. "Omnis congregatio et secta diabolica." 

More books ricochet off the ceiling and rain down with broken spines and cracked covers. It's like being under a rock slide, the sink offering almost no protection.

"Ergo, draco maledicte―Sam, look out!"

A rusted machete has started wobbling against the wall. Sam spots it just as it comes loose. He flattens himself to the ground, and the blade just misses his head. It careens into the hallway, a resounding clang the only proof that it eventually stops.

"Et omnis legio diabolica―"

"―Adjuramus."

"NO!"

Dean's howl plunges the room into silence. It's earlier in the exorcism than they expected, but Cas edges out from under the sink anyway. Pages torn from the books are still settling on the floor, some singed, others crumpled. In the middle of this hellish snow globe, Dean sits hunched, shoulders heaving as the fire on his arm gutters out.

Sam clears his throat meaningfully. Cas responds with a nod. They collect fresh blood from their wounds and, at the same time, slap bloodied palms side-by-side to the right of the mirror.

Silver light flares through their fingers as an otherwise invisible sigil burns to life. A line reaches out from it to another, then another, catching sigils like fuse wire until the room is ringed with white hot Enochian script as Hannah’s spell crackles to life.

As soon as Dean crumples to the floor, they rush to his side. Castiel hauls him into his lap. The bruises on Dean's face are already coloring, and he's barely conscious, but exhausted eyes make contact and hold steady. Determined.


	5. Chapter 5

"Dean," Castiel sighs with relief. It's him, no doubt about it. Their bet paid off. Even if they couldn't actually exorcise Dean from his own body, the attempt disrupted the connection between him and the Mark enough that his human side could take over. Cas holds him against his chest while Sam, now kneeling beside them, peels away burnt fabric. The cleansing light of the spell is enough for them to see the outlines of charred and blistered skin, the Mark of Cain a smoking crater on his forearm. Dean struggles, protesting incoherently, but Sam ignores him. He braces Dean's arm against his stomach while grabbing a small jar from the pocket of his flannel shirt. He unscrews the lid with his teeth, spitting it aside before thumbing muddy salve over the Mark.

"Somnus potuit, donec signum loqui." *

Three times Sam repeats the phrase, and at the end of the third, Dean goes boneless. For a terrifying second, Cas wonders if that was it. If it's over. Dean's body has taken all it can take and is giving up. But before despair has a chance to set in, Dean heaves a shuddering breath. 

"Sammy?" he mumbles into Cas's shoulder. 

Choking back tears, Sam thumps a hand on Dean's back. "Right here, big brother." 

"Is it gone?"

"No, no, just roofied. We're still working on something permanent, but I made enough salve to give us a few days, at least."

Dean nods, though it's barely more than a twitch of his head. "I'm tired."

"Let's get you to bed, then." Cas sits up straighter, lifting Dean until he can get his legs under both of them. 

"Not here." Dean struggles to push away.

Cas tightens his grip. "Yes, here." 

Sam grabs an arm, and between the two of them, they hoist Dean upright. Cas takes his weight while Sam kicks a path clear of debris. Naturally, Dean protests the whole way, but he's brought up short when Sam shoves the bed aside, revealing a partially constructed Devil's trap beneath it. More importantly, there's an eye-bolt mounted to the wall behind the headboard. As Cas lowers him to the mattress, Dean eyes the engravings on the manacle hanging from the chain. It's the same one they'd used on Crowley, but Dean almost seems surprised. Gingerly, he takes the chain between thumb and forefinger to examine it.

Instead of answering Dean’s unasked questions, Sam just says, "Where's the First Blade?" then starts a pat-down. Surprisingly, Dean cooperates. He drops the chain and lifts both arms, familiar enough with his part in this kind of drill to look unimpressed by Sam's brisk efficiency. Cas climbs behind Dean to help out, which mostly involves supporting Dean's arms.

"Trunk." 

"So you don't have to stay in contact with it to…?" Sam taps his chest, indicating the place where Dean had been stabbed.

"Keep my insides from becoming my outsides? Nope. Nothing that fancy."

Sam and Cas trade relieved looks. It's one hurdle cleared, but there are still many more ahead.

Dean's got a switchblade in his collar, stashed in the zip pocket meant for a hood. Other than that, Dean's back is clean. Which Cas already suspected, but, since he wasn't thinking clearly the last time he was touching that part of Dean's body, it's best to confirm. He adds the blade to the growing pile of knives and lock picks.

"Where's the Impala?" Cas asks as he slides away, not wanting to think too much about how different it was to share this bed with Dean just a few minutes earlier.

Dean starts to speak then stops abruptly. He stares at the floor, head lolling forward. For a minute, they're both sure he's fallen asleep, but then he straightens up, eyes wide. "I dunno." 

Sam sighs, hands on his hips. "Seriously?"

"Dude, I can just zap to her. I don't need a map!"

"Is it within a day's drive?"

"No. I think. Maybe?" He scrubs his face with his palms like he's trying to scrape off the exhaustion. "Oklahoma City?" All the talking seems to have alerted his nervous system to the massive burn on his arm. He recoils suddenly as the pain kicks in. "Awesome." 

"Well, we'll pull up the LoJack and figure it out that way. Anything else hidden on you that we should know about?"

Dean snorts weakly. "There's an old rubber in my wallet." 

"I don't think you'll be able to MacGyver your way out with that." Sam’s mouth curves up slightly on one side, but he manages to hold onto his air of authority. The chain rattles as he pulls it away from the headboard. "Lay down."

"Not gonna buy me dinner first?"

Cas turns in surprise. "Is your appetite returning already?" Dean is looking at him like he's grown a second head. Which he hasn't, of course, but he's been with these two long enough to understand the colloquialism. "Oh, I get it." Face warming, he focuses on unlacing Dean's steel-toed boots while Sam secures the manacle around his wrist. "That was a joke built on the expectation that purchasing a meal obligates your dining companion to provide sexual favors."

As soon as the words are out of his mouth, he realizes that he's drawn attention to the fact that Dean's jeans are still unzipped. Thankfully, Sam looks away quickly, heading to the desk. Wanting to spare them additional awkwardness, Cas reaches out.

"Here, I'll―" 

"―No!" Dean snaps. Cas backs off, frowning as Dean fumbles through doing the job one-handed. For his part, Sam is either pretending to be busy or continuing to ignore the entire situation. 

It's probably best to follow Sam's lead. Cas joins him at the desk to help unpack the rest of the supplies they'd hidden there.

"Strictly speaking, this is the angelic equivalent of a human child being sent to their room without supper." 

"Huh?" Sam takes the can of spray paint Cas offers. It's half empty where they used it for the part of the Devil's trap which could be hidden under the bed, but they need to finish it now that Dean's inside. Exhausted though he may be, there's no telling how long their efforts will keep the Mark at bay. 

"This spell." Cas motions to the sigils on the wall as he explains, mostly for Dean's benefit. "It's often used as a means of punishing angels for minor transgressions. It powers them down so they can reflect without intrusion from the Host."

Dean struggles upright, his pants back in order. However, the burnt arm forces him back down. "Fuck. That mighta been handy, you know... once or twice." 

"The holy oil was a much better option." Cas spots a knife sticking out the top of Dean's right boot. "No angel is ever taught the whole spell, since, in a more powerful form, it's also used to help secure Heaven's prison. You could say it's our version of solitary confinement." He tugs out the blade then removes the boots themselves. Dean may not lace them tight, or even all the way, but they have still molded themselves to his feet. They also smell foul. In the human way, not the demonic, but stink is stink. Once he's got the boots off, he loads them up with the weapons and drops everything outside the bedroom door where it can't be reached.

"So how'd you do it if you didn't know all of it?" Dean asks.

"Hannah helped." 

Dean snorts, rolling his head against the pillow. "Bet she loved that."

There's nothing Cas can say to the contrary, so he doesn't. Instead, he goes to the medicine cabinet for first aid supplies. Thankfully, those are as abundant as beer in the bunker, if not as faithfully restocked. It takes a minute to clear away debris so he can use the night stand as a work surface, arrange the desk chair without breaking any of the fresh lines in the Devil's trap, and jockey around the chain to get Dean's arm into position, but he manages despite the paint fumes starting to cloud the air. "This is going to hurt," he says when he's settled in.

"Dunno why you're bothering. It'll heal on its own. You should've seen the gash I got the―"

"It doesn't matter." Sam says, shaking the paint can. "We don't know how much of that comes from Lucifer being an angel." He finishes the outer circle of the trap, straightening to examine his work. After a couple of quick touch-ups, he lobs the can into the wastebasket. "It'd be just our luck to save you from the Mark of Cain only to have you die from gangrene."

"Fine." Dean shrugs. "Knock yourself out."

"Here." Sam leans to the other side of the bed, grabbing the lamp Cas had been hoping to use as a bludgeon. Now they use it to get a better look at Dean's forearm. As they do, Sam inhales sharply, and with good reason. The wound is a mess: blood clotted amongst rendered body fat, the salve having emulsified it all into a nauseating sludge. For his part, Dean is unimpressed, like it's someone else's arm laying there cooked like a sausage. Dean shrugs, turning his attention to the ceiling and ignoring the fact that Sam's gone to lean over the sink.

Dean's most likely faking disinterest, but Cas truly isn't bothered by any of it. This is no different than bathing or elimination as far as he is concerned: unpleasant but necessary. He starts at Dean's wrist, cutting away the remains of the burnt sleeve.

Unwrapping a sterile bandage, he douses it in Betadine and begins carefully cleaning the skin. This primitive treatment? Now this bothers him. Not so long ago, he could've healed Dean with a touch instead of relying on tinctures and snake oil. Inefficiency is the name of the game when you're human, though. The only good thing is that burns aren't particularly complex, at least not when compared to a curse that nearly predates humanity.

Cas is on his second gauze pad when Sam comes back, hands stuffed in his pockets as he bounces stiffly on the balls of his feet. "Right. I'm, uh, gonna go grab some ice for that." He puts the jar of salve on the table, tapping the lid to draw Cas's attention, then bolts from the room. Some of the tension leaves with him, though it's a stretch to say what lingers is anything like relaxed.

"Surprised he made it this long," Dean mutters. The limits of his disinterest are tested as Cas peels away a piece of fabric that fused with his skin. It leaves behind a raw, angry patch, beads of plasma bubbling to the surface as Dean breathes through the pain.

"I understand why seeing your injuries would upset Sam, but I would expect it to be more troubling for you."

"Why?"

"Aside from the third degree burns on your arm?" He looks Dean in the eye, weighing his words carefully. "Sam didn't witness your mother's death. You did."

Dean flops his unchained hand. "I was four, man. I barely remember it. Sam got the whole nine when Azazel torched Jess. Kid didn't sleep for months."

"I'd forgotten." Returning to the burn, Cas discovers more melted fabric and trades the gauze for tweezers. "That's curious."

"What? The memory stuff? You think it's from yoinking out your grace?" 

"I don't see much value in specu―" A chunk of skin comes loose, enough to uncover muscle. Dean hisses, eyes bulging as he bites down on a growl. "Sorry." 

"Not my first rodeo. Just get it over with."

Nodding, Cas blots the area a few times―enough that he can plan a course―then starts plucking, methodical and efficient with each chunk of flesh he ends up tearing away. Dean takes it better than anyone should, sweat glazing his forehead while the rest of his body remains perfectly still.

"Anyhow," Dean adds through gritted teeth. "That's not what I meant."

"About?" 

"Sam. He probably needed to go somewhere to laugh his ass off."

"At what?" Cas's brain catches up as his mouth finishes the question. "Oh." Right. Dean without the Mark's influence would not be comfortable with the fact they'd done… whatever it was they'd been doing. Cas is unsure what to say, so, again, he says nothing. That's quite the useful strategy. "Okay. That's the last of it." The tweezers, bloodied and greasy, slip from his fingers onto the bedside table. He flushes the wound with more Betadine, using the wastebasket to catch the run-off.

Exactly as Cas suspected, Dean doesn't take the discussion further. Instead, he points to the burn, drawing a loop in the air above the salve still covering it. "Why didn't you clean off the goop?" 

"It disrupts the connection between you and the Mark." 

"How's it do that?"

"Sam compounded it using ingredients from spells meant to break both demonic and angelic influences." His eyes trace the Enochian characters still burning in a blue-white band along the walls. "Much like combining an exorcism with these sigils, only a more direct method."

"Yeah. Okay. And?"

"We are, as they say, covering our bases."

That earns him a half-smile, and Dean closes his eyes while Cas sweeps the rest of the mess into the trash. For a minute he thinks Dean might be intending to get some rest, start repaying his sleep debt now that the curse is no longer sustaining him. Cas would certainly appreciate some rest himself. Now that the adrenaline is wearing off, he's starting to become acutely aware of every ache in his human body, especially his throat. 

"Well," Dean says, eyes still closed, "you're gonna have to wash it off if you insist on me healing the old fashioned way. If you don't clean under it, it'll get infected, and if it winds up needing amputated, Sam'll beat us both with the bloody stump."

"I suspect that would make a rather impractical weapon, though it does paint a vivid mental picture."

"That was kinda the idea."

Cas scans the walls, double-checking the wards and the chain. Then, kneeling on the floor, he verifies the integrity of the Devil's trap (that's not a lesson he needs to learn twice). "I suppose it would be safe to go ahead and remove it. Do you feel up to it?"

"This thing's been a monkey on my back for months. A couple more minutes ain't squat."

"Alright then." He settles back into the chair and pours alcohol onto more gauze while Dean obediently offers up his arm. The alcohol begins dissolving the salve almost immediately. Cas is still dabbing the area when the change happens. Dean's muscles tense, but they don’t go taut, landing somewhere between fight and flight. When Cas looks up, he sees that Dean's pupils have also narrowed, gaze completely locked on his face. For a moment, he understands what it must feel like to be an insect caught in a spider's web. "Well," he says, mostly to himself, "now I can tell the difference." 

He's startled when, instead of attacking, Dean pinches his cheek with the unchained hand. 

"Aww, 'fraid you were humping the Mark and not the man? That's adorable." Cas swipes Dean's hand away, and Dean chuckles. "Would it help if I made you a sandwich?" 

It's so tempting to counter that, pointing out Dean's history of having sex with any willing partner. Or, worse yet, the girl Dean worries wasn't as willing as he'd convinced himself through a haze of whiskey and Vicodin. It's a closely guarded moment of shame, something Dean has never shared with anyone, but Cas knows all of the sins that were laid bare in Hell. Alastair didn't let anything so inconsequential as evidence get in the way of the systematic destruction of his protégé's psyche.

Cas could use that against him, the ultimate rebuttal to his own concerns about that night with April, but he won't. Dean deserves peace, and unearthing that memory would haunt him long after the demon problem is resolved. So he goes for the nonverbal approach, yanking Dean's arm into his lap and not exactly taking pains to avoid turning it backwards at the elbow.

"Oh, look at you, acting all butch now that you've got me chained up. I thought you didn't like getting rough in the sack? Or is it okay so long as you're the one dishing it out?"

Castiel says nothing, and, amazingly, the demon leaves it at that. There's no more lewd commentary, no struggle to escape, token or otherwise. It just lays there, as still as death, and Cas knows all too well how that looks. He knows how close he came to having to sacrifice himself to get Dean out of Hell. It’d been days before he was strong enough to occupy Jimmy's vessel. Now, he's removing thousands of the cells he'd nearly died to repair, all in a desperate attempt to undo the Mark's damage. 

That's when he realizes they've still not asked the most important question.

"Was it Crowley or the First Blade that brought you back?"

Dean shrugs. "Yeah." 

"Could you be a bit more specific?"

"Well, I was dead, he gave me the blade, then I wasn't."

Castiel sighs, shaking his head. "You can be so frustrating."

"I've got a natural talent." The demon watches as the debrided wound is flushed. When nothing but healthy skin remains, he clears his throat. "So, when's Sammy gonna slip me the hot blood injections?"

"He isn't," Cas replies, opening a fresh bandage. "His body was primed to complete the final trial. It's likely he was purged of the effects when he was healed, but there's no guarantee. We're not risking his life."

"But that's what he wants! Samuel of Lawrence, patron saint of Oprah fans, martyr to nerds."

Cas shakes his head again, this time much more emphatically. "Closing Hell is off the table until we have a better understanding of the long term effects of the spell." He blots the wound dry of plasma, then, denying the demon the last word, slathers on a thick coat of the warding salve. He quickly repeats the incantation, and, as soon as he finishes, Dean relaxes, muscles yielding to exhaustion once more.

Hoping to prevent further discussion, Cas avoids eye contact as he cleans up the first aid supplies. He's confident in the decisions he and Sam made during Dean's absence, but he doesn't have the energy left to explain them. Eventually, of course, but not tonight. Unfortunately, Dean speaks up just as Cas gets one foot out the door.

"So you're doing it?" 

It seems more like a condemnation than a question. As if Cas is somehow unfit for the task. He wants to scream, or, better yet, hit something. Violence would be a pointless overreaction, but that doesn’t make it any less attractive. It must have something to do with all the unspent testosterone in his blood. He should study human physiology more carefully in the future. Clearly, his technical understanding as an angel is not translating into a practical skillset now that he's not running a mini-mart.

Biting down on the frustration, Castiel replies, "Yes."

"Don't."

"Maybe I would change my mind if you gave me a sandwich," he snaps, turning around. The way Dean sags in defeat takes all the joy from it. Cas stands there, watching him trip over guilt so palpable it's apparent even in his breathing. Finally, he sighs. "Get some rest. We're both going to need it."

"Right, so don't waste your energy on stupid stuff."

"It's not stupid if it works!"

"And so what if it does? I lose the black eyes but not the beauty mark?" Dean gestures at his bandaged arm, only just refraining from actually slapping it. "All we're doing is postponing the inevitable."

"And what's wrong with postponing it?" He comes back into the room, pacing back and forth with a sudden, restless energy that he knows will cost him later.

Surprisingly, Dean lowers his voice. "A human body ain't strong enough."

"Who told you that?"

"Crowley."

That’s the last straw. Cas stomps over to him. "And you believed him?" he asks, incredulous.

"Isn’t me yakking up organ soup in the dungeon enough proof for you?"

"Cain must have gone through it, too. Clearly, he survived it."

"Sure, by becoming the big demon on campus."

Cas drops to the foot of the bed, one leg folded under him as leverage in case he needs to move quickly. "Dean, your bloodline was cultivated so that you would be a vessel capable of hosting an archangel. The _complete_ form of an archangel!" He yanks up Dean's arm. "This," he points at the Mark, "this… scribble… it's nothing more than an echo of Lucifer's power. Even if it can't be removed, God literally designed you to contain much more!"

Dean pulls his arm away, propping himself up on his elbow. "Right. Fine. So how many people do I gotta kill before you realize that you're literally full of shit?"

Cas jumps up, kicking the chair across the room as he lets out a dry scream of frustration. It takes a few aborted swallows before he can get past the pain in his throat. The pain that wouldn't be there had Dean's demonic form not attempted to strangle him (which also wouldn’t have happened if Dean had long enough to realize that, when God singles you out for saving, it's a safe bet you might be a little special). But he pulls himself together before turning back to Dean. "I'm not arguing with you."

"And I ain't arguing with you." Dean replies, a hitch in his breath. It's startling, and it takes Cas a moment to realize Dean isn't reacting to his frustration. He's upset in his own right. "It's just… when you're staring down the barrel of a gun, things get a lot clearer. Things you want." He rolls away, tucking his head into the pillow as much as he can with one arm stretched behind him.

"Like what? What do you want, Dean?"

A minute takes an hour to pass, or so it seems. 

"Are you really gonna make me spell it out?" 

Cas takes a step closer, then another, but Dean says nothing until he is nearly at the bed. It's his knee bumping the side that jostles an answer loose. Slowly, Dean rolls over.

"Look, man, I'm not asking you to off me again. I get that ain't gonna happen. Besides, the Mark'll do it eventually."

"It brought you back."

"So I can kill more," he says, scrubbing his face with his knuckles. He stops with his chin held in his palm, voice still somewhat muffled. "As long as I kill, I feel awesome, but the minute I stop, it's downhill fast."

"Did Crowley tell you that, too?" 

Dean shakes his head. "No. He just confirmed what I'd figured out on my own."

"Then it's like an addiction. That's all the more reason for us to perform the ritual of purified blood. You won't have to go through withdrawal because—"

"—No. Look. Come here." Dean waves him over, patting the mattress by his chest. Cas hesitates, then he decides any risk is worth hearing what Dean has to say. He sits where he was asked, and Dean leans in close. "It wasn't a mistake, the Mark. It let me take out Abaddon." Cas starts to object, but Dean raises a finger, demanding silence. "You gave up your wings, but you got Heaven back on its feet, too. We did good," he says, something akin to pride spreading over his face. "And we've done enough. It's time we got benched." He stops to take a deep breath, letting it out haltingly. "You and me."

Surprised, Cas replies, "You and me? You mean... together?"

Dean finds a proper smile for that, broad and damn near glowing. "Yeah. We get the hell out of Dodge. Go somewhere warm. Maybe a beach. You ever been to a beach? And I don't mean to do recon for Dad, but for actual relaxation?"

"I can't say that I have."

"Me neither, and I want to. Smell the surf. Sleep on the sand. Piss off some hermit crabs or something."

Castiel tries to picture that: peace, quiet, and uninterrupted time with Dean to _exist._ Maybe they could get a boat. Go fishing. Dean could teach him how. After dark, they'd warm themselves while the fish cooks on a hot stone inside the fire. Just the thought of that kind of simplicity makes his chest ache, but reality is impossible to ignore. "Sam would find us."

"Eventually, but I know how he thinks." Dean rests his chained hand over the one Castiel has on the sheet. It happens quickly, and without preamble. He just keeps right on talking, as if it's something utterly routine. "I can cover our tracks good enough to give us a few weeks. By the time he gets there, it'll be too late."

As Cas lets that statement sink in, Dean squeezes his hand. It's like he's squeezing his heart. 

"So you're not asking me to kill you. You just want me to watch you die."

"No, Cas, I'm asking you to help me live while I still can." With his free hand, he lightly slaps his chest then does the same to Castiel's. "While _you_ still can. Because I know damn well, when I'm gone, you're gonna hunt. It's in your blood now."

Some rudimentary instinct drives Castiel to thread their fingers together. It has to be that, because he certainly wasn't planning to do it. Evidently, Dean wasn't expecting him to do it, either. He makes a small, pained noise, then pulls at him. Confused, Castiel looks at their hands, then at Dean, then back to their hands. Dean nods, pulling harder this time. No, not hard. Not really. If anything, it's gentle, just... insistent. So Cas yields to it, letting Dean guide him until his head is laying over his heart.

He can hear it beating like this, a steady thump with a rhythm older than time. But Dean's breath is labored, like Castiel's own was when he was trying to hold back tears. Is Dean going to cry? Is that's what is about to happen? Dean will cry because, what? Because they are holding each other? The shock of it pins Castiel in place.

"If we get a wiggle on," Dean whispers, "we could be out of here before Sammy gets back from hiding in the kitchen." 

In the time between heartbeats, Castiel allows himself to believe that leaving is the right thing to do: be spontaneous, selfish. Needy. But even now, reeling at the possibility of having a truly human life, he knows they can't just go. He lifts his head, dragging himself away from temptation.

"Not tonight. We need rest," he hastens to add. "We need to put together a real plan. Something more difficult for Sam to untangle."

Dean's face fractures into another smile, such depth of gratitude it's overwhelming. Castiel swallows his grief, knowing how much this is going to hurt. But before he can get off the bed, Dean is tugging him up, mouths meeting softly. It's different without the threat of violence; Castiel has no problem understanding what's happening this time around.

Hearing a noise in the hall, Dean stiffens, quietly taking Sam's name in vain. Castiel pulls away, Dean hanging on until he's at arm's length.

"I'll see you in the morning," Cas says, giving a final squeeze before letting go.

Dean nods and rolls to his side, arms folding over his middle as his eyes close. 

**

Cas is surprised to find that Sam is not in the hallway after all. He pulls the door shut behind him, realizing that it could have been anything making the sound. After all, it's an old building. 

Instead of going straight to his room, he stops by the kitchen long enough to grab a bottle of water. He doesn't feel thirsty, but, too often, by the time he identifies hunger or thirst, he's let himself go too long without fuel. He wants to develop healthy habits.

He sips on the bottle as he walks towards his room. It's a good room: the walls are clean, the brick sound, the floor well-scrubbed. Hannah had even pitched in to help them prepare it, getting down on her knees with a scrub brush and marveling how the labor had both tired and invigorated her vessel. 

A Man of Letters once used that room. Now a former angel has claimed it as his own. Perhaps he will die there after contributing his knowledge to the fight, documenting as much as he can before his brain begins to slow to a mortal capacity. He will even hang things on the walls which mean something to him, but not tonight. Tonight, he requires well-deserved rest to prepare himself for the difficult conversation with Sam.

Only, as he opens the door to the room, he realizes that rest is still far from his grasp, and he's not going to have time to prepare for anything. Sam is sitting at the empty desk, his expression one of barely-contained grief mixed with understandable rage.

"So, when are you two leaving?" Sam asks.

It's difficult loving a Winchester, regardless whether that love is philia or eros. Castiel succeeds in not sighing aloud. He closes the door behind himself before going to the foot of his bed, sitting on sheets that still smell faintly of packaging plastic. 

"We're not."

Sam grimaces as he shakes his head bitterly, then starts to stand up before catching himself. "Wait, what?"

"The sigils are dampening its power, but the Mark has already regained control."

Sam's response is predictable, and almost as disheartening as the truth when Cas realized it himself. "But… I just... I heard what he was saying. What you said. And I'm sorry for eavesdropping, I was trying not to." He finally catches himself, hands on his hips. "What the hell?"

"That wasn't Dean."

"My brother is emotionally constipated, but every once in a while, he manages to own up to things he's feeling instead of denying them or drinking them away."

"I know." He stares at Sam, and Sam stares back, and they say nothing, but they communicate everything they need to.

Finally, Sam sighs. "You're sure?"

"My..." Cas takes a moment to find the right word. "My gut? It tells me it's true."

"Okay." He nods, pulling his mouth down as he scrubs over it with his hand. "Okay. Still going for Plan A, then?"

"Yes." 

They look at each other again, the only sound in the room that of frustrated breath. Then Sam nods. 

"Right. Okay. I'll see you in the morning."

Not even bothering to check the clock to see what time it is, Cas says, "I'll see you when I wake up."

Sam snorts out a halfhearted laugh and pats him on the shoulder as he leaves.

Castiel exhales, a weight leaving him that he hadn't realized was there until now. He has a room of his own. A blank slate upon which to build a future. And, maybe, someday, that future will include Dean as more than a friend or a brother.

But that day is a long way away, if it ever comes at all. Before Castiel can leave his own mark on this space, he needs to help get the Mark off of Dean. His blood will be in Dean's veins, and it feels fitting to do that. To rebuild him a second time even if it's only in this limited, human way. It will go some distance towards making up for Castiel's mistakes. The rest, well, he'll figure that out eventually.

**Notes for the Chapter:**

> * "Somnus potuit, donec signum loqui." = Uneducated attempt at Latin for "Sleep, mark of Lucifer, until you are permitted to speak."

**Author's Note:**

> I started this during the Season 9 summer hellatus. To say my writing mojo has been running thin would be an understatement. In addition to the Demon!Dean storyline being much shorter than anyone expected for "The _Year_ of the Deanmon," I was surprised that Metatron's capture wasn't used to reopen the gates. Evidently, they needed an excuse to keep the angels grounded. I was also a bit bummed that we never got to see Dean zapping around from place to place like a proper demon. I headcanon that he had the power to do it, but the last vestiges of his humanity made him prefer using Baby whenever possible (even if he wasn’t keeping her clean). Also, Dean finally has the power to see an angel's true form, and he doesn't even make a joke about it? Yeah... I had to.


End file.
